Tools
Tools
Tools
INFORMATION
TECHNICAL INFORMATION 1
CUTTING-OFF & GRINDING WHEELS
TECHNICAL INFORMATION
SHAPE SPECIFICATION SYSTEM
BF 27 BF 29 BF 41 BF 42
RECOMMENDED PRACTICE
PORTABLE GRINDERS
GRINDING ROUGH WORK
• Do not use a cutting-off wheel for
snagging
• Do not work with the side of a wheel,
you will cut the reinforcing cloths
• Work at an angle of 10 to 30º with
a longitudinal action
CUTTING-OFF
• Arrange the workpiece so that a uniform section can be cut
NO YES NO YES
INFORMATION
TECHNICAL
2 TECHNICAL INFORMATION
FIXED MACHINE
DOWNSTROKE HEADS
• Lay out the shape parts in order to
have a constant section
• Avoid any wedging of the grinding
wheel
• Make sure the wheel is cleared NO YES
AUTOMATIC FEED
• In the case of thick parts, use the
reciprocating motion of the carriage
OSCILLATING HEADS
OPERATING MODE
1. Oscillating
2. Cutting-off
Do not use this type of machine
with a downstroke action
EXAMPLE:
V04/2016 indicates production in the 2nd quarter of 2013
and advised usage before the 2nd quarter of 2016 INFORMATION
TECHNICAL
TECHNICAL INFORMATION 3
PERSONAL PROTECTION
Safety goggles, ear defenders, safety gloves, dust masks and, if conditions are severe, additional face
protection. Leather aprons and safety shoes must be worn.
GENERAL PRECAUTIONS
Safety instructions provided by the Sparks should be directed away from the face and
body, if possible towards the floor. Dust extraction
machine manufacturers must be equipment must be used whenever it is available.
followed. Where fitted, all guards, The instructions for use given by the abrasive
covers and hoods must be in place on manufacturer must be followed e.g. ‘Not to be
used without a support’, or ‘Not to be used for wet
the machine during grinding, and should grinding’. The workpiece must be firmly fixed before
not be modified in any way. Abrasives grinding starts. Check all abrasives visually before
should not be used near inflammable use and make certain that the product is suitable for
the application. No modifications should be made to
material or in an environment where abrasive products after delivery.
there is a risk of explosion.
When using a portable grinder always switch it off
and allow the spindle to stop completely before
putting the tool down. Wet grinding should only be
carried out on machines designed for this purpose
and with abrasives designated as suitable for this
type of operation.
INFORMATION
TECHNICAL
4 TECHNICAL INFORMATION
OPERATING SPEEDS
Norton products are designed and tested for certain applications and operating speeds. Choose a wheel
suitable for the application material. Suitable materials are indicated on the wheel label. Before mounting
the grinding or cutting-off wheel on the machine, ensure that the operating speed of the machine does not
exceed the maximum operating speed as it is marked on the product.
SPEED CONVERSION FOLLOWING EN 12413
WHEEL
DIAMETER MAXIMUM OPERATING SPEED (RPM)
(mm)
35 40 50 63 80 100 125 140 160
50/51 13400 15300 19100 24100 30600 38200 47750 53500 61200
63/65 10650 12150 15200 19100 24300 30250 37900 42500 48500
100/102 6700 7650 9550 12100 15300 19100 23900 26800 30600
115 5850 6650 8350 10500 13300 16650 20800 23250 26600
125 5350 6150 7650 9650 12250 15300 19100 21400 24500
150/152 4500 5100 6400 8050 10200 12700 16000 17850 20400
180 3750 4250 5350 6700 8500 10650 13300 14900 17000
200 3350 3850 4800 6050 7650 9550 11950 13400 15300
230 2950 3350 4200 5250 6650 8350 10400 11650 13300
250/254 2700 3100 3850 4850 6150 7650 9550 10700 12250
300/305 2250 2550 3200 4050 5100 6400 8000 8950 10200
350/356 1950 2200 2750 3450 4400 5500 6850 7650 8750
400/406 1700 1950 2400 3050 3850 4800 6000 6700 7650
450/457 1500 1700 2150 2700 3400 4250 5350 5950 6800
500/508 1350 1550 1950 2450 3100 3850 4800 5350 6150
600/610 1150 1300 1600 2050 2550 3200 4000 4500 5100
750/762 895 1050 1300 1650 2050 2550 3200 3600 4100
800/813 840 960 1200 1550 1950 2400 3000 3350 3850
900/914 750 850 1100 1350 1700 2150 2700 3000 3400
1000/1020 670 765 960 1250 1550 1950 2400 2700 3100
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 5
TROUBLESHOOTING
CUTTING-OFF WHEELS
WHEEL DOES NOT CUT
Cause In case of blue cutting: wheel too hard or too thick
Solution Use softer or Norton Thin Cut wheels, check peripheral speed
EXCESSIVE WEAR
Cause In case of white cutting edge: wheel too soft
Solution Use machine with more power, reduce pressure on the machine
Solution Use more radial pressure & swing the wheel forwards and backwards
6 TECHNICAL INFORMATION
GRINDING WHEELS
WHEEL DOES NOT CUT
Cause Wheel too hard, wheelglazing
Solution Use Norton Alu wheels which counteract loading & wheelglazing
EXCESSIVE WHEELWEAR
Cause Wheel too soft
Solution Use machine with more power, reduce pressure on the machine
UNBALANCE
Cause Dirty flanges
TECHNICAL INFORMATION 7
SAFETY ADVICE
DOs
Always handle & store wheels carefully. Cutting-off wheels should be stacked horizontally
✓ DO & flat, preferably on a steel base plate. Depressed centre wheels should be placed on top
of each other or stored in the original packaging
✓ DO Always visually inspect all wheels before mounting for possible damage in transit
Always use a safety guard & ensure that it is correctly positioned & securely fitted. It should
cover at least one half of the wheel & protect the operator in the unlikely event of a wheel
✓ DO
breakage. NON-REINFORCED CUTTING-OFF WHEELS SHOULD ONLY BE USED ON FIXED
MACHINES & SHOULD BE CORRECTLY GUARDED.
Always switch ‘OFF’ the power at supply source &/or remove the plug from the socket before
✓ DO
changing the wheel
Always ensure that the spindle speed of the machine does not exceed the operating speed
✓ DO
marked on the wheel
Always use the correct wheel mounting flanges & ensure that they are undamaged,
✓ DO
clean & free from burrs
✓ DO SEE EN 12413
Allow newly mounted wheels to run at operating speed, with the guard in place,
✓ DO
for a reasonable time before cutting or grinding
Always wear appropriate safety clothing such as DUST MASK, GLOVES, EAR PROTECTION,
✓ DO
OVERALLS & SAFETY SHOES
Always have machine speeds checked regularly, especially after maintenance or repair.
✓ DO Machines fitted with speed control devices (Governors), must be properly maintained
at all times
Check tension of driving belts, where fitted, on a regular basis. Belts must be kept tight
✓ DO
to ensure full power transmission.
Put portable machines in suitable cradles, when not being used, to avoid damage
✓ DO
to the wheel
Always use a portable machine in a comfortable position, where the workpiece is well
✓ DO
balanced & the machine is well supported
Keep the working area around cutting & grinding operations clear. It is very dangerous
✓ DO
if an operator trips & falls with an operating machine in his hands
INFORMATION
TECHNICAL
8 TECHNICAL INFORMATION
DON’Ts
✘ DON’T Tighten the mounting nut or locking flange excessively. To do so can distort the flanges
✘ DON’T Use mounting flanges which are incorrect, damaged, dirty or burred
✘ DON’T Use blotters with depressed centre wheels less than or equal to 406mm (EN 12413)
✘ DON’T Apply side pressure to cutting-off wheels. You should not bend the wheel
Stop the wheel by applying pressure to the periphery or face. Always switch the machine off
✘ DON’T
& allow the wheel to stop revolving
✘ DON’T Apply excessive pressure onto the wheel so that the driving motor slows down
✘ DON’T Grind on the side of cutting-off wheels or depressed centre wheels below 4,0mm thickness
Drop or lower a portable machine by the cable or airline onto the floor. A wheel can be easily
✘ DON’T cracked, if it is put down hard, by the weight of the machine. This is a common cause of
wheel breakage
✘ DON’T Grind with a depressed centre grinding wheel at an angle below 30 degrees to the workpiece
Use a machine in a position where you do not have full control of the machine & you are not
✘ DON’T
well balanced
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 9
COATED ABRASIVES
TECHNICAL INFORMATION
WHAT IS A COATED ABRASIVE?
Modern coated abrasives are the product of an extremely technical process developed through many
years of research and development. They remain, however, a product composed of three basic elements:
a flexible or semi-rigid backing to which abrasive grains are bonded by an adhesive.
SIZER COAT
ABRASIVES
BONDS
MAKER COAT
BACKING
10 TECHNICAL INFORMATION
ABRASIVE GRAIN SIZE
After the crude abrasives have been crushed, the The European standard of grit sizes is the FEPA
grains are separated (graded) into standard particle grading system. All FEPA grit sizes are preceded
sizes using screens carefully made from silk with the letter ‘P’, i.e. P180 etc.
threads of exact size and number per square inch to In the USA a different grading system called CAMI
ensure extreme accuracy. The grit number (mesh is used. This chart provides a comparison between
number) appearing on the coated abrasive backing FEPA and CAMI grades and also shows average
represents the number of openings per linear inch particle sizes in microns and inches.
in the final screen. Grits 240 and finer, called flours,
are graded by hydraulic separators, air classifiers Additionally, some products produced for the
and levigating tanks. woodworking and floor sanding markets are
identified with a ‘grit symbol’. Although use of this
symbol is infrequent, the backing of these products
contain both the mesh number and the grit symbol.
,00197 50,0 – – – – – –
TECHNICAL
TECHNICAL INFORMATION 11
ABRASIVE GRAIN SIZE
ALUMINIUM OXIDE, GARNET,
PARTICLE PARTICLE EMERY
SILICON CARBIDE, ZIRCONIA ALUMINA GLASS
SIZE IN SIZE IN GRADING SYSTEMS COMP. GRIT POLISHING PAPER
INCHES MICRON CLOTH
CAMI FEPA SYMBOL PAPER
,00204 52,5 – P280 – – – –
,00209 53,5 240 – 7/0 – – –
,00217 55,0 – – – – – –
,00228 58,5 – P240 – – – –
,0023 60,0 – – – – – –
,00254 60,5 – P220 – – – –
,00257 66,0 220 – 6/0 2 – –
,00304 78,0 180 P180 5/0 3 – 00
,00363 93,0 150 – 4/0 – Fine –
,00378 97,0 – P150 – – – 0
,00452 116,0 120 – 3/0 – – –
,00495 127,0 – P120 – – – 1
,00550 141,0 100 – 2/0 – Medium –
,00608 156,0 – P100 – – – 11/2
,00749 192,0 80 – 0 – – –
,00768 197,0 – P80 – – – F2
,01014 260,0 – P60 – – – M2
,01045 268,0 60 – 1/2 – Coarse –
,01271 326,0 – P50 – – – S2
,01369 351,0 50 – 1 – – –
,01601 412,0 – P40 – – – 21/2
,01699 428,0 40 – -11/2 – – –
,02044 524,0 – P36 – – – 36
,02087 535,0 36 – 2 – Extra coarse –
,02426 622,2 – P30 – – – –
,02488 638,0 30 – 2 /2
1
– – –
,02789 715,0 24 – 3 – – –
,02886 740,0 – P24 – – – –
,03530 905,0 20 – 31/2 – – –
,03838 984,0 – P20 – – – –
,05148 1320,0 16 – 4 – – –
,05164 1324,0 – P16 – – – –
,06880 1764,0 – P12 – – – –
,07184 1842,0 12 – 41/2 – – –
INFORMATION
TECHNICAL
12 TECHNICAL INFORMATION
NARROW BELTS & WIDE BELTS
The results achieved when sanding with belts depends on several factors including:
• The machine condition & available horsepower
• The belt speed
• The grinding pressure
• The contact wheel
• The choice of the belt in relation to the shape of the part & material type
• The use of coolant (when machine & belt allows)
BELT SPEED
The speed of the belt has a direct relationship with its cut rate, as well as the amount of heat generated,
the surface finish achieved, and the stress on abrasive grain. Some abrasives like zirconia alumina and
ceramic support much higher stresses because they have a better resistance to uncontrolled fracture.
Some materials are more sensitive to heat generation. The chart below gives the recommended speed
range according to material.
Sintered metals & carbides 8-15m/s Grey cast iron & cast steel 30-40m/s
Glass, porcelain & special steel 8-15m/s Brass, copper, zinc, bronze & tin 25-35m/s
GRINDING PRESSURE
The amount of grinding pressure depends on:
• The force used
• The size of the contact area between the belt & the workpiece
• The backing on which the belt runs (generally a contact wheel)
Higher pressure increases the cut rate and the amount of heat generated increases the stress on the
individual abrasive grain (a minimum stress is necessary to achieve a controlled fracture of the abrasive
grain), and generally generates a rougher finish.
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 13
CONTACT WHEELS
Many machines use contact wheels as a backing for belts. Contact wheels are generally covered with
rubber, polyurethane, steel, rubber foam, felt, or compressed canvas, and are classified from soft to hard,
with or without serrations. Using a different type of contact wheel has a direct effect on the end results.
• Harder contact wheels provide a higher cut rate, a rougher surface finish & generate a much more uniform
surface than softer contact wheels. They are used with stiff belts for a faster cut
• Softer contact wheels provide lower cut rates, a better surface finish & follow the contours of the part.
They are generally used for finishing contoured parts or for generating slightly rounded surfaces. They are
much less hard wearing on the belt & its joint
The design of the contact wheel will also have an effect on the contact area, which in turn affects grinding
pressure.
• Contact wheels with a larger diameter act softer & should generally be used on larger surfaces
• Serrated contact wheels act harder but should generally be used on smaller surfaces
HARD SOFT
Aggressiveness increases as angle increases Contact surface decreases as lands decrease giving a more
aggressive, harder wheel
JOINT TYPES
Belts are made with a standard joint design best adapted to the product and its main application:
Butt joint with tape Overlap joint with no topskive Overlap joint with extra topskive
INFORMATION
TECHNICAL
14 TECHNICAL INFORMATION
NORaX AN INNOVATIVE TECHNOLOGY
NORaX is the innovative coated abrasive technology new layer of sharp abrasives. This continuous
from Norton. The innovation lies in the abrasive replacement of dulled abrasives results in longer
layer: a multi-layer coating of abrasive is engineered life, higher cut rates, and a more consistent surface
into a 3D pattern. These patterns give a controlled finish throughout the belt life. Also, contributing to
contact surface between the abrasive and part that this higher performance, NORaX is also covered
optimises belt performance. with a surface powder grinding aid that increases
cut and life while decreasing grinding temperature.
NORaX works like a grinding wheel on a cloth
backing. As the belt wears, dull abrasive particles
are removed from the belt surface to expose a
For more information on NORaX please contact your local Sales or Customer Service Representative.
TECHNICAL INFORMATION 15
BACKING TYPES
CLOTH FIBRE
Cloth backings are more durable than paper, offer Fibre backings, made of multiple layers of
greater resistance to tearing, and tolerate continual impregnated paper, are very hard and strong,
bending and flexing during use. Norton use yet provide sufficient flexibility for the intended
traditional woven cloth in the manufacture of their applications. 0,8mm thick fibre has the greatest
coated abrasives. The backing has construction and strength of any backing used for coated abrasives.
finishing characteristics designed to make it ideally This backing is used on resin bonded fibre
suited to a specific application. The standard cloth discs designed for heavy duty portable grinding
weights used in coated abrasives are indicated by a applications.
letter code which appears immediately after the grit
size on the finished product backing.
COMBINATION
J-weight Combination backing, constructed by laminating
The lightest and most flexible cloth backing, this light cloth and stiff E-weight paper, is used where
backing is used where finish and uniformity of the resistance to tearing and breaking is a requirement.
surface are more important than stock removal. Primarily utilised on products designed for
Ideal for finishing, blending and where flexibility and chipboard/MDF sanding.
conformity are required, such as contour work or
curved surfaces.
FILM
X-weight Polyester is used as the backing media for Norton’s
Stronger and relatively stiff when compared range of precision graded microfinishing products.
to J-weight, this backing is used on products Film backings can be used wet or dry and have
designed for coarse grit stock removal applications excellent resistance to chemical attack, while being
through fine grit finishing and polishing. Consistent tear resistant and durable.
productivity, relatively good finishes and long
product life are characteristics of products made on
X-weight backings.
SPECIAL COATED SURFACE TREATMENT
Y-weight
Stronger and more resistant to longitudinal splitting NO-FIL TREATMENT
than regular drills cloth, Y-weight backing is used In order to provide even further resistance to
on products designed for severe applications, such loading, some Openkote paper products are given a
as narrow belt grinding of hand tools and wide belts special surface treatment of zinc stearate after the
sanding of lumber and particleboard dimensioning. sizing operation. Such products are ideal for sanding
between sealer coats on furniture, sanding after
primer coats on automobiles, removing varnish
from wood, and numerous other operations where
conventional abrasive products fail prematurely due
to loading.
Norton’s trademark for products utilising this
treatment is No-Fil.
INFORMATION
TECHNICAL
16 TECHNICAL INFORMATION
SURFACE FINISH & GRINDING EFFICIENCY VARIABLES
SURFACE FINISH VARIABLES
Changes in any one of many factors can affect the surface finish generated by a product. The purpose of
this chart is to show the effect on surface finish by changes in single factors of product specifications.
Arrows have been used to signify the trend direction. The length of the arrows have no significance as the
effect of each variable factor will not be the same. The chart is meant to be general in nature and to show
direction or trend.
10. Grinding Aid Dry Water Oil Solubles Straight Oils Grease
TECHNICAL INFORMATION 17
CUTTING EFFICIENCY
Although general in nature, this chart can serve as a useful guide as to what effect a change in a single
given factor in the specification will have on the cutting efficiency of coated abrasive products. Arrows
have been used to signify the trend direction. The length of arrows has no significance. Some important
machine and setup parameters have also been included since they do have significant impact on product
performance.
Coarse Fine
4. Grit Size
Close-Coated Open-Coated
8. Coating Method
Smaller Larger
11. Diameter
High Low
12. Pressure
18 TECHNICAL INFORMATION
SAFETY ADVICE
SAFETY IN THE STORAGE & USE OF COATED ABRASIVES
TRANSPORT & STORAGE GENERAL PRECAUTIONS
All coated abrasives should be handled carefully. Safety instructions provided by the machine
Damage can be caused by mishandling, which manufacturers must be followed. Where fitted,
should be avoided. all guards, covers and hoods must be in place on
the machine during grinding, and should not be
Coated abrasives should be stored in dry, frost
modified in any way. Abrasives should not be used
free conditions. They should be kept away from
near infl ammable material or in an environment
heat sources, cold, damp walls, doors or windows
where there is a risk of explosion.
and should not be in direct contact with the floor.
Temperatures and humidity should be between Sparks should be directed away from the face and
18°C and 22°C and 45%-65% relative humidity. body, if possible towards the floor. Dust extraction
Coated abrasives should not exposed to direct equipment must be used whenever it is available.
sunlight. Products should be kept in their original The instructions for use given by the abrasive
packaging until immediately before use. Once manufacturer must be followed e.g. ‘Not to be
unpacked, they should be stored in a way which used without a support’, or ‘Not to be used for wet
avoids distortion. grinding’. The workpiece must be firmly fixed before
grinding starts. Check all abrasives visually before
use and make certain that the product is suitable for
PERSONAL PROTECTION the application. No modifications should be made to
Safety goggles, ear defenders, safety gloves, dust abrasive products after delivery.
masks and, if conditions are severe, additional face When using a portable grinder always switch it off
protection. Leather aprons and safety shoes must and allow the spindle to stop completely before
be worn. putting the tool down. Wet grinding should only be
carried out on machines designed for this purpose
and with abrasives designated as suitable for this
type of operation.
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 19
TUNGSTEN CARBIDE BURRS
DOs
✓ DO Select the appropriate shape, diameter & cut style for the application
✓ DO Fix the maximum length of the burr in the collet (recommended max 10mm overhang)
✓ DO Check that the burr is running true in the grinder before use
DON’Ts
Allow burr to become too hot, causing braze to weaken (applies to burrs where head
✘ DON’T
diameter is greater than shank diameter)
20 TECHNICAL INFORMATION
BEARTEX
PRODUCT SELECTION - BY MACHINE
STATIONARY MACHINES
Product selection guide & Starting Points recommendation
F2303 HS
Plain Discs n/a F2520 VF A n/a
Med A
Convolute Reduction
D19 SF DCS DMA 5AM
Wheels Bushings
Polybond Reduction
C150-H10BTM n/a C240-D4BTM
Bench Wheels Bushings
Grinder
Reduction
Flap Wheels n/a F2301 Med A F2501 VF A
Bushings
Unitised Reduction
U2301 8AM U2401 6AF U4401 2SF
Wheels Bushings
F2303 HS
Plain Discs n/a F2520 VF A n/a
Med A
Convolute Reduction
D19 SF DCS DMA 5AM
Wheels Bushings
Reduction
Flap Wheels n/a F2301 Med A F2501 VF A
Bushings
Reduction
Unitised Wheels U2301 8AM U2401 6AF U4401 2SF
Bushings
BELT EQUIPMENT
TECHNICAL INFORMATION 21
BLENDING & REQUIRED
MACHINES PRODUCT DEBURRING CLEANING
FINISHING ACCESSORY
FEED-THROUGH EQUIPMENT
Surface Blend
DSB Coa DSJ Med Superflex Med n/a
Belts
Sheet/Coil
Reduction
Processing Flap Wheels n/a F2301 Med A F2501 VF A
Bushings
Machine
Convolute Reduction
D18 SF DCS DMA 5AM
Wheels Bushings
Rotary Disc/
Surface Blend
Planetary DSB Coa DSJ Med DSJ Med n/a
Discs
Disc Machine
AUTOMATED EQUIPMENT
Plain Discs n/a F2303 HS Med A F2520 VF A n/a
Convolute Reduction
D18 SF DCS DMA 5AM
Wheels Bushings
Polybond Reduction
C150-H10BTM n/a C240-D4BTM
Wheels Bushings
Rotary
Machine Surface
DSB Coa DSJ Med Superflex Med n/a
Blend Belts
Unitised Reduction
U2301 8AM U2401 6AF U4401 2SF
Wheels Bushings
Flap Reduction
n/a F2301 Med A F2501 VF A
Wheels Bushings
Convolute Reduction
D18 SF DCS DMA 5AM
Wheels Bushings
Polybond Reduction
C150-H10BTM n/a C240-D4BTM
Wheels Bushings
Straight-Line
Machine Surface Blend
DSB Coa DSJ Med Superflex Med n/a
Belts
Unitised Reduction
U2301 8AM U2401 6AF U4401 2SF
Wheels Bushings
Reduction
Flap Wheels n/a F2301 Med A F2501 VF A
Bushings
Surface Blend
DSB Coa DSJ Med Superflex Med n/a
Belts
Polybond Reduction
C150-H10BTM n/a C240-D4BTM
Wheels Bushings
MAX
RPM
SPEC
CHECK
SPEC CHECK
Did you pick the most efficient solution?
The most cost effective method usually involves getting the job done fast and efficiently.
The most dramatic savings come from labour expenses, rather than material costs.
INFORMATION
TECHNICAL
22 TECHNICAL INFORMATION
BLENDING & REQUIRED
MACHINES PRODUCT DEBURRING CLEANING
FINISHING ACCESSORY
AUTOMATED EQUIPMENT
Surface Blend
DSB Coa DSJ Med DSJ Med n/a
Discs
Convolute Reduction
D18 SF DCS DMA 5AM
Wheels Bushings
Polybond Reduction
C150-H10BTM n/a C240-D4BTM
Wheels Bushings
Reduction
Flap Wheels n/a F2301 Med A F2501 VF A
Bushings
F2303 HS
Plain Discs n/a F2520 VF A n/a
Med A
Unitised Reduction
U2301 8AM U2401 6AF U4401 2SF
Wheels Bushings
PORTABLE MACHINES
BLENDING & REQUIRED
MACHINES PRODUCT DEBURRING CLEANING
FINISHING ACCESSORY
STRAIGHT-SHAFT TOOLS
F2303 HS
Plain Discs n/a F2520 VF A Mandrels
Med A
Convolute
D16 SF DCS DMA 5AM Mandrels
Wheels
Polybond
C150-H10BTM n/a C240-D4BTM Mandrels
Wheels
Drill
Flap Wheels
n/a F2301 Med A F2501 VF A n/a
(Spindle)
RapidStrip R4101 S Ex
n/a n/a Mandrels
Wheels/Discs Coa
F2303 HS
Plain Discs n/a F2520 VF A Mandrels
Med A
Convolute
D19 SF DCS DMA 5AM Mandrels
Wheels
Straight-
Unitised
Shaft U2301 8AM U2401 6AF U4401 2SF Mandrels
Wheels
Grinder
RapidStrip R4101 S Ex
n/a n/a Mandrels
Wheels Coa
Flap Wheels
n/a F2301 Med A F2501 VF A n/a
INFORMATION
(Spindle)
TECHNICAL
TECHNICAL INFORMATION 23
BLENDING & REQUIRED
MACHINES PRODUCT DEBURRING CLEANING
FINISHING ACCESSORY
STRAIGHT-SHAFT TOOLS
Flap Wheels
n/a F2301 Med A F2501 VF A n/a
(Spindle)
Die Grinder
Unitised Wheels U2301 8AM U2401 6AF U4401 2SF Mandrels
F2303 HS
Plain Discs n/a F2520 VF A Mandrels
Med A
RapidStrip R4101 S Ex
n/a n/a Mandrels
Wheels Coa
R4101 S Ex SpeedLok
SpeedLok Discs DSB Coa DSJ Med
Coa Holders
R4101 S Ex SpeedLok
SpeedLok Discs DSB Coa DSJ Med
Right Angle Coa Holders
Die Grinder/
Mini Grinder Specialised F2303 HS SpeedLok
U2301 6AM U4401 2SF
SpeedLok discs Med A Holders
Satinex R4101 S Ex
Satinex Wheels F2200 A Coa F2300 Med A n/a
machine Coa
INFORMATION
TECHNICAL
24 TECHNICAL INFORMATION
BLENDING & REQUIRED
MACHINES PRODUCT DEBURRING CLEANING
FINISHING ACCESSORY
BELT TOOLS
VIBRATING TOOLS
F2303 HS Self-Grip
Plain Discs n/a F2520 VF A
Med A back up pads
Orbital
Sander
Surface Blend Self-Grip
DSB Coa DSJ Med DSJ Med
Discs back up pads
Hand F2504 VF
Rolls F2300 Med A F4804 UF S n/a
Applications A LL
Warning - Do not use a product which was not designed specifically for that tool.
Always verify that the speed rating of the product meets or exceeds the rating of the tool!
MAX
RPM
SPEC
CHECK
SPEC CHECK
Starting point recommendations can vary depending on the level of aggression required,
by choosing a different product grade
Depending upon performance results, other specifications may be substituted on the basis
of product testing.
The best practice is to test at least 2 variations of specifications to obtain the desired result.
TECHNICAL INFORMATION 25
PRODUCT SELECTION- BY APPLICATION
SHORTCUT TO FINDING THE RIGHT PRODUCT…
For deburring or cleaning/finishing, or on completely new operations, the product specifications listed
below are recommended as starting points.
Depending upon performance results, other specifications may be substituted on the basis of product
testing.
We believe that the best practice is to test at least 2 variations of specifications to obtain the desired result.
DEBURRING
Medium Burrs Light Burrs
CONVOLUTE WHEELS
Series 1000 Long Life 1 - 8 SF C4408 Series 1000 Long Life 1 - 7 SF C4408
UNITISED WHEELS
HAND PADS
F2302 Heavy Duty Extra Cut Tan Pad F2504 VFA LL Maroon General Purp Pad
WOOD CONDITIONING
Sanding and Shaping Finishing and Rubbing
CONVOLUTE WHEELS
Series 1000 Long Life 1 - 8 SM C4308 F2801 Micro Fine S Gold Pad
INFORMATION
TECHNICAL
26 TECHNICAL INFORMATION
CLEANING AND FINISHING
Clean / Medium Grain Finishing Fine Grain Finishing
CONVOLUTE WHEELS
DSS Surf Fin S/C Med Wheel C4302 DCS Clean/Finish S/C Fine Wheel C4401
or or
Series 1000 Long Life 1 - 6 SM, C4308 Series 1000 Long Life 1 - 6 SF C4408
UNITISED WHEELS
FLAP WHEELS
Med Grit Aluminium Oxide F2301 Fine Grit Aluminium Oxide F2401
HAND PADS
F2504 VFA LL Maroon General Purp F2801 Micro Fine S Gold Pad
or
HAND PADS
F2302 Heavy Duty Extra Cut Pad F2504 VFA LL General Purpose Pad F2801 Mfine S Pad
Tan Maroon Gold
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 27
MATERIAL IDENTIFICATION
PRODUCT SHAPE COLOUR GRADE GRIT TYPE SIZE FIBRE STRENGTH
Aggressive
Maroon Medium A Aluminium Oxide 120
Brown Extra Cut Aluminium Oxide 80
Black Medium S Silicon Carbide 60
Gold Micro Fine A Fused Alumina 1000
Bearflex Maroon Very Fine A Aluminium Oxide 600 Nylon
Gray Ultra Fine S Silicon Carbide 320
Maroon Very Fine A Aluminium Oxide 280
High Strength Nylon
Maroon Medium A Aluminium Oxide 100
Gray Super Fine Silicon Carbide 600
Aggressive
Surface Blending SCM
Maroon Heavy Medium Aluminium Oxide 80 Nylon
Discs and Belts
Brown Coarse Aluminium Oxide 50
Dark
Extra Coarse Aluminium Oxide 46
Brown
Rapid Strip Black Extra Coarse Silicon Carbide 36 Nylon
White Super
White None
Gloss
Aggressive
Floor Pads Thick Maroon Red Buffer Aluminium Oxide Nylon
Line General Purpose
Blue Blue Super Clean Aluminium Oxide
Green Super
Green Aluminium Oxide
Scrub
Black Black Super Strip Aluminium Oxide
White White None
Least - Most
Aggressive
28 TECHNICAL INFORMATION
SAFETY ADVICE - DO’S & DON’TS
For your safety you should ensure that you are fully aware of how to safely use abrasives
✓ DO Read the safety instructions provided by the abrasives and equipment supplier
Examine all products before mounting and periodically during use for possible defects
✓ DO
or damage (core flatness, fatigue cracks, undercutting, arbor hole damage...)
Check that correct mounting devices are used and that they are clean, undistorted and free
✓ DO
from burrs
✓ DO Avoid clogging and uneven wear to ensure that the product is working efficiently
Ensure that all machines using abrasives meet the requirements of the current european
✓ DO
machinery directives-CE
Be aware of the hazards likely during the use of abrasives and observe the recommended
precautions to be taken:
• Bodily contact with the abrasive product at operating speed
• Injury resulting from product breakage during use
✓ DO
• Grinding debris, sparks, fumes and dust generated by the grinding process
• Noise
• Vibration
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 29
SAFETY ADVICE - DO’S & DON’TS
For your safety you should ensure that you are fully aware of how to safely use abrasives.
✘ DON’T Use a machine that is not in good working order or one with defective parts
✘ DON’T Force the abrasive onto the mounting device or modify the size of the mounting hole
✘ DON’T Use mounting flanges which are not clean and flat
✘ DON’T Start the machine until the guard is in place and fastened securely
✘ DON’T Grind on the part of the product which is not designed for the operation
✘ DON’T Start the machine with the workpiece in contact with the abrasive product
✘ DON’T Stop the abrasive by applying pressure to its surface, let it stop naturally
30 TECHNICAL INFORMATION
BONDED ABRASIVES
TECHNICAL INFORMATION
WHAT IS A GRINDING WHEEL?
A grinding wheel is a precision tool with thousands ABRASIVES
of cutting points. It consists of abrasive grains held Modern synthetic abrasives allow accurate control
in a matrix of bond and separated by pores. The over the physical properties and form of the
abrasive grains are the cutting points while the abrasive grain. This helps to ensure that grinding
purpose of the bond is to hold the individual grains wheels can be manufactured with consistent cutting
together. The pores (hollow spaces between properties.
adjacent abrasive grains and the bond) serve to
provide clearance for coolant penetration and metal Norton offers a comprehensive selection of
chips removed in the grinding process. abrasive types to provide a wide range of specific
grinding characteristics. This is necessary
When the wheel is rotated at grinding speed and for maximum efficiency in the large variety of
applied to the workpiece, the abrasive grains cut the operations demanded by the industry today.
material that is being ground, removing the material
in small chips. Abrasive Grain Size
The grain or grit size is most important in
Under the action of the forces imposed during determining a wheel’s ability to achieve the required
grinding the abrasive cutting points are worn fl at, surface finish and remove stock. The size is
resulting in the points becoming blunt. This causes designated by a number which increases as grain
an increase in friction, and a build up of heat. size decreases.
The increase in grinding forces causes either the For example 10 grit has a median size of about
abrasive to fracture, exposing new cutting edges, 2,0mm and 60 grit 0,25mm.
or fractures the bond bridges holding the abrasive Standard sizes are used in all Norton wheels as
grains. In the latter case fresh abrasive grains are specified in the European Standards laid down by
exposed to cut the workpiece. FEPA.
In normal vitrified grinding applications the wheel An ideal grinding abrasive has the ability to stay
has to be dressed. sharp with minimum point dulling, and when dulling
By varying the properties of the abrasive, the type begins it fractures revealing new sharp cutting
of bond, the make-up of the wheel, it is possible edges. Abrasive grains used in the manufacture of
to produce grinding wheels with a vast range of bonded abrasives come in three main categories.
different grinding characteristics.
TECHNICAL INFORMATION 31
ABRASIVE TYPES
ABRASIVE DESCRIPTION
TYPE
A This is a particularly tough form of aluminium oxide. Its toughness is due to the presence of 3% of titanium
oxide in the abrasive. Fired at low temperature the abrasive retains its natural brown colour. Fired at high
temperature further oxidation of the titanium oxide takes place which changes the normal brown colour
to a grey-blue. Because of its toughness, regular brown alumina is suitable for grinding high tensile strength
materials, specifically off-hand grinding (bench grinding wheels) & sharpening stones.
19A A blend of A & 38A abrasives. This abrasive gives a grinding action that can be compared to the average
of its components. It is supplied in some standard tool room wheels, used for surface, cylindrical, centreless
& miscellaneous grinding on less heat sensitive steels.
38A White fused aluminium oxide (99,8% pure). The most friable & cool cutting of the aluminium oxides.
This abrasive is supplied in all types of standard range wheels ideal for use on hard & heat sensitive steels
& alloys. It has traditionally been used for sharpening high-speed steel & cast alloy tools & cutters.
38A is used for cylindrical, surface & internal grinding of tools, dies & gauges.
57A Semi-pure brown fused aluminium oxide (98% pure). The higher purity of 57A makes it a good general
purpose abrasive. Its versatility enables it to be used for grinding steel parts in both soft & hard states,
especially on large cylindrical & centreless operations. U Treatment (U57A) is a ceramic coating applied
to this abrasive to increase its durability in resin bonded cutting-off wheels. It is used in the advanced range
resinoid cut-off wheels.
86A Pink aluminium oxide is a highly refined form of alumina containing a small proportion of chromium oxide.
This addition makes 86A a little tougher than pure white, increasing the strength along the shear planes.
This abrasive is available in a range of mounted points & wheels.
SGB A blend of premium abrasives that include a medium concentration of ceramic Norton SG.
3SG A blend of premium abrasives that include a high concentration of ceramic Norton SG.
5SG A blend of premium abrasives that include a very high concentration of ceramic Norton SG.
37C Crystolon silicon carbide abrasive. Supplied mainly in the resin bonds of advanced wheels used for grinding
grey iron, non-ferrous metals & in vitrified bonds for grinding non-metallic materials, such as rubber & stone.
39C Crystolon is the highest purity silicon carbide abrasive. It is ideal for grinding cemented carbide cutting tools,
fired ceramics & glass, where it provides advanced performance.
BOND TYPES
VITRIFIED
Vitrified bonds are the most common precision grinding bond. Porosity and strength of the wheels made
with this bond give high stock removal along with their rigidity helping to attain high precision. Not affected
by water, acid, oils or ordinary temperature variations. The most common vitrified bonds are:
V V is the original high temperature vitrified bond, usually used where tougher acting wheels are required
VS VS is a very versatile, low temperature, high performance vitrified bond system used in almost all applications
but predominately for tool room, centreless, cylindrical, & surface grinding
VTECH Low temperature, very technical bond, used with conventional abrasives & recommended for high tech
applications to maximise performance & dressing parameters
VX VX bond provides improved corner/form holding for most applications – it is the first choice bond for our
premium abrasives
VXP Induced porosity VX bond suitable for large contact areas & surface grinding
INFORMATION
TECHNICAL
32 TECHNICAL INFORMATION
BOND TYPES
ORGANIC
These bonds are used in two types of wheels. Firstly, wheels used on portable or fixed machines for the
rapid removal of metal. Secondly, cutting-off wheels either un-reinforced or reinforced, for use on portable
or fixed machines. The most common organic bonds are:
SNAGGING WHEELS & CUPS
B & B3 Foundry wheels: multi-purpose bond that gives satisfactory results on most applications
B28 Foundry wheels: high level bond suitable for most technical applications requiring high powered machines
CUTTING-OFF WHEELS
BF1 Specific bond ensuring the best quality of cut in dry or wet conditions
BF3 New generation bond assuring the best wheel life in dry cutting operations; versatile & long wheel life.
Ideal for heavy duty operations
B24 New generation bond used on silicon carbide cut-off wheels that gives the best performance & the ultimate
cut quality on non-ferrous metals in wet conditions
B25 Standard multi-purpose bond that offers durability & freeness of cut in a wide variety of materials
& applications. Can also be used in wet cutting on softer grades
B26 New generation bond used on aluminium oxide cut-off wheels that gives the best performance
& the ultimate cut quality on ferrous metals in wet conditions
B65 Traditional bond gives good performance & long wheel life in dry cutting conditions
WHEEL GRADES
The grade indicates the relative holding power of the bond, which holds abrasive grains in a wheel.
This is represented in the specification by letters running through the alphabet from hardest to softest.
The following rules should be followed with regard to grade:
USE SOFT GRADE USE HARD GRADE
• For hard materials such as hard tool steels • For soft materials
& carbides
• For small or narrow areas on contact
• For large areas of contact
• For longer wheel life
• For rapid stock removal
E F G H I J K L M N O P Q R S T U
CYLINDRICAL/CENTRELESS
SURFACE GRINDING
ID GRINDING
TOOL GRINDING
THREAD GRINDING
NON-REINFORCED ORGANIC
REINFORCED ORGANIC
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 33
AVAILABILITY SUMMARY
ABRASIVE TYPE BOND ABRASIVE COLOUR
A–19A VS Brown
38A VS White
STOCK TO BE REMOVED
This affects the choice of abrasive size and
bond type.
High stock removal rates, as in fettling operations,
require coarse grit wheels, typically 12 to 24 mesh.
Fine finishes and tight limits on finished workpiece
geometry require finer grit sizes.
Final surface finish is often achieved by ‘spark
out’. No further infeed is applied and the wheel is
allowed to grind until the majority of the grinding
sparks cease.
INFORMATION
TECHNICAL
34 TECHNICAL INFORMATION
SURFACE FINISH
Usage Key
SURFACE FINISH & GRIT SIZE
Highly recommended
42 1,10
32 0,80
26 0,70
21 0,50
16 0,40
14 0,35
11 0,25
8 0,20
7 0,17
6 0,14
5 0,12
4 0,10
3 0,08
2 0,05
METRIC
MIN FORM 0,75 0,50 0,40 0,25 0,20 0,18 0,13 0,10
(mm)
RADIUS
IMP INS ,030 ,020 ,015 ,010 ,008 ,007 ,005 ,004
The achievable surface finish in any grinding ACHIEVING IMPROVED SURFACE FINISHES
operation is highly dependent upon the grit size
By changing the wheel dressing technique, it is
of the grinding wheel. The following chart shows
possible to achieve finer surface finishes than those
the range of surface finishes achievable when
shown. As well as reducing the dresser infeed per
using grinding wheels of different grit sizes on
revolution of the grinding wheel, it is also possible
conventional precision grinding applications,
to reduce the infeed and traverse rate when
together with the minimum form radius that can be
grinding, thus reducing the stock removal rate.
ground using each grit size.
Obviously this approach will have limited application
Other factors can affect the surface finish achieved. in production grinding but it can be very useful in
In particular: tool room work.
• Production grinding applications, with higher stock
removal ranges, will give surface finishes at the
coarser end of the range
• Plunge grinding applications will often require the
selection of a grit size one size finer than shown
• Dressing techniques & the type of material can
also affect the surface finish achieved
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 35
THE GRINDING MACHINE
The type of machine can effectively define the grinding contact area and the ease with which grinding fluid
can be applied to the grinding zone.
The power available on the machine governs the stock removal rate. The greater the power available,
the harder the grade of wheel that is required for efficient operation.
Any deterioration in the condition of machine bearings and slideways will lead to vibration and,
consequently, premature wheel breakdown. This can, in part, be overcome by using a harder grade wheel
and/or a tougher abrasive but the only effective solution is to maintain the machine as recommended
by the machine manufacturer.
*The maximum peripheral speed (m/s) specified for the wheel must never be exceeded
The size of workpiece can also affect the grinding contact area. In general, the larger the workpiece,
relative to the grinding wheel diameter, the larger the contact area, requiring softer grade wheels.
GRINDING FLUID
Dry grinding with vitrified wheels require wheels one or two grades softer than when wet grinding.
36 TECHNICAL INFORMATION
SINGLE & MULTI-POINT DIAMONDS
Diamonds are the first choice where close tolerances, fine finishes, speed and flexibility are required. Since
diamond dressing is primarily a machining operation rather than a crushing operation, the surface formed
on the wheel is closer than that obtained from mechanical dressers. This results in a slower cutting wheel
with better form holding characteristics and superior finish control.
By varying the depth of cut per pass made by the diamond and changing the traverse rate, different wheel
surfaces, and hence different cutting actions, can be achieved.
The following are general recommendations for dressing with single-point diamonds.
ROUGHING FINISHING
The diamond should always be applied at the centreline of the wheel with a 5°-15° drag angle.
DIAMOND SIZE
The size of diamond is important when selecting a dressing tool and several factors are relevant in this
selection, e.g. large, coarse grit wheels require a larger diamond than smaller, fine grit wheels. If a fine
finish is required, the use of a diamond which is too large can adversely affect the finish and cancel the
effect of fine grit selection. The trend today is away from single-point dressers and towards multi-point
dressers employing a matrix shape to suit the form required.
A useful formula for determining single-point & multi-point diamond size is:
Wheel diameter (mm) x Wheel thickness (mm)
Diameter x Thickness
Carat
(mm)
Diameter
Diameter x Thickness
Carat
(mm)
Diameter
COOLANT
Dressing with diamonds should always be carried out using a copious supply of coolant. The coolant should
always be turned on fully before the diamond touches the wheel. The diamond life will deteriorate rapidly if
it is allowed to become hot and then cooled rapidly as can be experienced with an intermittent coolant flow.
TECHNICAL INFORMATION 37
REDUCTION RINGS
Plastic reduction rings may be used to adapt
grinding wheels to fit on various spindle sizes.
These rings reduce the bore hole size, allowing the Reduced bore (mm)
wheel to be safely mounted on a spindle with 15
a smaller diameter.
• Reduction rings should never come in contact
with the flange
• Reduction rings should not be used on wheels
of thicknesses less than 6mm, nor greater
than 50mm
• Always use one reduction ring on each side of 20
the wheel when the wheel is thick enough to Wheel bore (mm)
allow correct seating
• Never use reduction rings to reduce the hole
below the minimum specified in the FEPA
safety code
50,8 35 07660704766
32 25 07660717540
32 20 07660717538
20 16 07660717530
20 15 07660717529
20 13 07660717527
20 12 07660717525
20 10 07660717524
16 6 00510008919
INFORMATION
TECHNICAL
38 TECHNICAL INFORMATION
MOUNTING
A wheel should only be mounted onto the machine In most instances it is appropriate to tighten the nut
for which it was intended. The speed of the spindle or screws by hand with the correct tool (spanner
on which the wheel is mounted should not under or hexagonal socket key) until they stop turning.
any circumstances exceed the maximum RPM By adopting this technique it is very rare that the
speed specified for the wheel when it is full size. wheel would be under-tightened and impossible to
The wheel should fit freely, but not loosely, onto over-tighten the wheel. Bolts for mounting wheels
the spindle or spigot diameter of the fl ange plates. with inserted nuts should be long enough to engage
Wheels, blotting paper washers and fl anges should an adequate length of thread, i.e. equal to the thread
be free from foreign matter. Certain wheels have diameter, but must not protrude through the nut
a positioning mark (Mount Down or Mount Up) insert.
marked on them. Care must be taken to ensure For recommended designs of fl anges, refer to the
that this mark occupies the position stated by the FEPA Safety Guidelines.
manufacturer.
CAUTION
REDUCING BUSHES
After mounting or re-mounting a grinding wheel
Where a removable bush is used as a means of on a machine, stand well clear, ensuring that there
reducing the bore of an abrasive wheel, care must are no persons in line with the wheel and allow the
be taken to ensure the bushes should not project wheel to run free for two minutes. A re-mounted
beyond the side of the wheel and the wheel blotter. wheel should always be treated as if it were a new
The clamping faces of the fl ange plates MUST wheel.
clamp on the mounting washers attached to the
wheel and not on any part of the reducing bush.
Reducing bushes should never be used on wheels TYPE 06 CUP WHEELS – FIXED MACHINES
less than 6mm thick or on products with a back or The diameter of the fl ange and paper washer inside
web of less than 6mm. Never use plastic bushes on the cup must be smaller than the diameter of the
wheels used with portable grinding equipment. cup recess to avoid any risk of radial pressure
on the wheel. When used for work heavier than
MOUNTING WASHERS light tool and cutter grinding, the back fl ange may
be larger than that inside the cup but the recess
Blotters should be used with all grinding wheels diameter of both fl anges must be equal.
unless there is a specific exemption. Blotters should
be slightly larger in diameter than the mounting
fl anges and free from any scuffs, wrinkles or other MOUNTED POINTS & WHEELS
damage. The spindle dimensions of the mounted point must
be suitable for the collet being used, and the spindle
overhang corresponding to the machine speed
MOUNTING FLANGES
should be observed.
Mounting fl anges are designed to clamp the wheel
to the machine and transfer the driving forces from
TYPE 31 GRINDING SEGMENTS
the machine spindle to the grinding wheel. They
should be designed to take the driving forces away Segments are held by special chucks with suitable
from the area around the grinding wheel bore and provision for adjustment to compensate for segment
generally should be not less than one third of the wear. To prevent breakages segments should not
grinding wheel diameter. protrude more than 1,5 times their thickness from
the clamping chuck face, and should be mounted
Flange surfaces should be fl at, free from burrs, with markings uppermost.
bumps, bruises and other damage. Flanges should
be of equal diameter, have equal bearing surfaces
and be properly recessed or undercut.
The rear fl ange must be positively driven by the
machine spindle, being either keyed or shrunk onto
the spindle.
Flanges must run true to the machine spindle.
Clamping nuts (centre nut locking) should only be
tightened sufficiently to hold the wheel securely
without slippage and must not be over-tightened.
When fl anges are clamped by a series of screws,
they should be tightened in stages uniformly in a
diametric sequence.
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 39
WHEEL BALANCE
Most Norton grinding wheels are balance corrected The balancing procedure can be carried out either
to a minimum of ISO Standards. Precision grinding on a special balancing stand or in-situ on the
machines usually provide methods of accurately machine. The machine manufacturer’s instructions
balancing the complete wheel and fl ange assembly. should be closely followed. There are many
Modern production machines are now supplied methods of manually balancing the wheel assembly,
with automatic balancing systems, whereas, tool depending upon the number of balance weights in
room and older production machines still have to the wheel arbour. A typical ‘two weight’ balancing
be manually balanced, ensuring the best possible system technique is described below:
grinding performance from the wheel.
VERTICAL
VERTICAL
VERTICAL
LINE
LINE
LINE
LIGHT SPOT
LIGHT SPOT
LIGHT SPOT
BALANCE BALANCE
WEIGHT WEIGHT
BALANCE
WEIGHT
• Mount wheel between flange plates • Turn wheel assembly so that one balance weight is
• Remove balance weights from annular groove on approximately 45 degrees from the horizontal line
mounting flange (can also be set diametrically & release the wheel. Note the direction in which
opposite if preferred – ensuring the weights cancel wheel rotates, the weight may revolve upwards
each other out) towards the vertical line. In this instance the
weight should be moved down away from the light
• Dress periphery of wheel until running in spot (always adjust the weights in the opposite
perfect truth direction of rotation) to begin bringing the wheel
• Remove complete wheel assembly from the into balance. See illustration 1B
machine (after allowing sufficient time for the • Continue checking the weights, alternating
coolant to spin out) & fix assembly onto the between the left & right hand balance weights in
balancing mandrel turn. Repeat until the wheel remains stationary
• Place on balancing unit & allow to turn freely. in all positions. Move the weights a maximum of
When stationary, mark top centre (light spot) 3mm at a time, reducing this amount as the wheel
with chalk rotates slower. See illustration 1C
• Re-position the balance weights so that the • Continue until assembly remains static in all
bottom side face of each weight, that is furthest positions. Lock balancing weights in position &
from the light spot, forms a right angle i.e. 90°. remount assembly onto the machine spindle
See illustration 1A • Important: – Ensure the balancing ways (knife
edges or rollers) on the balancing stand are level
in all directions. Care must be taken to initially find
the true light spot of the wheel
INFORMATION
TECHNICAL
40 TECHNICAL INFORMATION
TROUBLESHOOTING
SOLVING SURFACE FINISH PROBLEMS
Many problems associated with grinding relate to surface finish defects. The following chart describes
some common surface finish problems, shows the probable causes and suggests remedies to cure
the problem.
CHEQUERED PATTERN
Cause Wheel out of balance
CHATTER MARKS
Cause Wheel out of truth
SPIRAL MARKS
Cause Dressing techniques
Solution Dress more frequently. Use more open, softer grade wheel
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 41
SAFETY ADVICE
SAFETY IN THE STORAGE & USE OF GRINDING WHEELS
Stringent safety standards are maintained throughout the manufacture of Norton Grinding Wheels.
To reduce the risk of accidents further, the law requires that certain basic precautions are taken
in the storage and use of abrasive wheels.
STORAGE CONDITIONS
During storage, grinding wheels must not be
subjected to:
• Exposure to humidity, water or other liquids
• Freezing temperatures
• Any temperature low enough to cause the
formation of condensation on the wheels
when moving from storage to an area of high
temperature
INFORMATION
TECHNICAL
42 TECHNICAL INFORMATION
SAFE WORKING PRACTICES
PERSONAL PROTECTION
Safety goggles, ear defenders, safety gloves, dust masks and, if conditions are severe, additional face
protection. Leather aprons and safety shoes must be worn.
TECHNICAL INFORMATION 43
SUPER ABRASIVES
TECHNICAL INFORMATION
DESIGNATION OF GRIT SIZES
Ra (µm) RA (µm) RA (µm)
FEPA US
JIS DWMI DIAMOND CBN SURFACE FINISH SURFACE FINISH SURFACE FINISH
MICRONS MESH
CARBIDE STEEL PLUNGE STEEL OSCILLATING
1181 16/18
1182 16/20 16
1001 18/20
851 20/25
852 20/30 20 24 24
711 25/30
601 30/35
602 30/40 30 36 36
501 35/40
426 40/45
427 40/50 40 46 46
356 45/50
301 50/60 50 50 50
50/80
251 60/70 60 60
252 60/80 60 60 80c 80c 0,6-0,9
213 70/80 80 80
181 80/100 80 80 100 100 0,4-0,7 1,0-1,1 0,9-1,1
80/120 110c
151 100/120 100 100 110 120 0,9-1,0 0,8-0,9
126 120/140 120 120 120 150 0,4-0,5 0,8-0,9 0,6-0,8
107 140/170 140 150 150 180 0,6-0,8 0,5-0,6
91 170/200 170 180 180 220 0,3-0,4 0,5-0,6 0,4-0,5
76 200/230 200 220 220 230
64 230/270 230 240 240 240 0,2-0,3 0,4-0,5
54 270/325 270 320 320 320
46 325/400 325 400 400 400 0,1-0,2
400/500 400 500 500
M63 40/60
M40 30/40 500 500
M25 20/30 700
15/25 800
M16 *10/20* 1000 600
*8/16* 1500
M10 *6/12* 2000 800
M6,3 *4/8* 2500
*3/6* 4000
M4 *2/4* 5000
M1 *0/2* 15000
INFORMATION
TECHNICAL
44 TECHNICAL INFORMATION
CONCENTRATION
The concentration is defined by a standard and indicates the weight of abrasive (in carats) contained
in 1cm3 of abrasive strip – 1 carat = 0,2 grams.
CONCENTRATION*
NUMBER OF CARATS/cm3 ABRASIVE WEIGHT PER cm3
DIAMOND ABRASIVE CBN ABRASIVE*
75 = T 3,3 = 0,66g/cm3
50 = Q 2,2 = 0,44g/cm3
SELECTION OF CONCENTRATION
The choice of concentration depends on the machining parameters:
CBN W T Q Q/T
COOLANT
Generally speaking, working with coolant is preferable to working without coolant because the coolant
reduces friction and dissipates heat generated by machining.
However, many sharpening operations are performed without coolant under good conditions and with
appropriate bonds.
Choice of coolant:
• DIAMOND wheel = pure water + 1,5% rust inhibitor or soluble oil
• CBN wheels = pure oil or water, always with 5 to 10% soluble oil
• For CBN wheels, changing from soluble oil to pure oil increases the service life of the wheel
TECHNICAL INFORMATION 45
• Mount wheel between hand-tightened flanges
• Using a dial indicator, tap the wheel lightly with a rubber or wooden block to minimize runout to less than
25 microns
• Tighten flange securely & recheck with indicator
• Allow a newly mounted wheel to operate for one full minute before grinding
• The use of one permanent mounting for the life of the wheel is recommended whenever possible:
– If the grinding machine has a tapered spindle, mount each straight, fl aring cup or dish wheel on a
separate collet or adapter
– When changing wheels the entire unit is removed, keeping the wheel in running truth
– When needed again, the entire unit can be placed directly on the spindle or arbor, thereby eliminating
the time & abrasive lost in retruing
TRUING – MAKING WHEEL ROUND & CONCENTRIC WITH THE SPINDLE AXIS
• Prior to truing the wheel, run a wax crayon over the wheel face. Important: do not use any liquid based ink
on super abrasive wheels
• Any crayon left on the wheel face after truing will reveal untrued areas
• Norton Brake Controlled Truing Devices are most commonly used to true Diamond & CBN straight,
cup & cylinder wheels
– Always use Brake Controlled Truing Device dry
– Bring the Diamond/CBN wheel & the truing wheel together until they almost touch
– Start the Diamond/CBN wheel to normal speed; start the truing wheel in the same direction
– Bring the two wheels together until they touch
– Make sure the truing wheel is spinning at time of contact
– Traverse the wheel back & forth at 10-20mm/s
– Downfeed 0,01-0,02mm at the end of each traverse
– At the end of truing, the Diamond/CBN wheel should be smooth & in truth
STICKS RECOMMENDED
46 TECHNICAL INFORMATION
TROUBLESHOOTING
USE RIGID WORK SUPPORT
• All workpieces should be supported firmly during the grinding process. Any amount of vibration will cause
wheel wear & produce chatter or wave marks on the ground surface
• On work ground between centres, centreholds should be properly prepared
• Minimise work overhang
• If the ground work is supported by a work finger, ensure the finger is strong enough to provide
vibration-free support
DRY GRINDING
BURNING (EXCESSIVE HEAT)
Cause Wheel loaded or glazed
POOR FINISH
Cause Grit size too coarse
CHATTER
Cause Wheel out of truth
TECHNICAL INFORMATION 47
WET GRINDING
BURNING (EXCESSIVE HEAT)
Cause Wheel glazed or loaded
Solution Re-dress wheel
Cause Poor coolant placement
Solution Apply coolant directly to wheel/workpiece interface
Cause Excessive material removal rate
Solution Reduce downfeed &/or crossfeed
Cause Wheel speed too high
Solution Slower wheel speed
POOR FINISH
Cause Excessive dressing
Solution Use lighter dressing pressure
Stop dressing as soon as wheel starts to consume stick rapidly
Cause Grit size too coarse
Solution Select a finer grit size
Cause Poor coolant flow or location
Solution Apply heavy flood so it reaches wheel/work interface
CHATTER
Cause Wheel out of truth
Solution True wheel; ensure it is not slipping on mount
Cause Wheel too hard
Solution Check specification
SLOW CUTTING
Cause Low feeds & speeds
Solution Increase feed rate; increase wheel speed (observe maximum wheel speed)
48 TECHNICAL INFORMATION
DIAMOND BLADES
TECHNICAL INFORMATION
OPERATING SPEEDS
MAXIMUM OPERATING SPEED
DIAMETER
MAX M/S MAX RPM
(mm)
100 80 15300
115 80 13300
125 80 12250
150 80 10200
180 80 8500
200 80 7650
230 80 6650
250 80 6100
450 63 2700
PERSONAL PROTECTION
Safety goggles, ear defenders, safety gloves, dust masks and, if conditions are severe, additional face
protection. Leather aprons and safety shoes must be worn.
TECHNICAL INFORMATION 49
TROUBLESHOOTING
DIAMOND BLADE DOES NOT CUT
Cause The segments are too hard for the material
EXCESSIVE WEAR
Cause The segment is too soft for the material (e.g. if a blade for hard material is used
to cut abrasive material)
Cause Excessive cutting pressure, overheating, material slippage, twisting or jamming in the cut
Solution Leave the blade to do the work, do not exert too much pressure & allow the blade to cool
regularly by leaving it to rotate away from the workpiece for a few seconds
SCORCHING OF SEGMENTS
Cause Excessive cutting pressure causing overheating. This is easily recognisable from the blue
colouring where the segments & the steel core are welded together
Solution Allow the diamond blade to cool regularly by rotating the blade away from the workpiece
for a few seconds
Solution Check if the diamond blade is suitable for the material. Alternatively use less cutting
pressure & let the blade do the work
UNDERCUTTING
Cause Undercutting occurs when the steel core wears faster than the segment, i.e. where the
segment & steel core meet. This is usually caused by materials that are highly abrasive.
The cutting debris is not removed sufficiently & the steel core is affected. Undercutting is
certain to occur if a diamond blade for hard materials is used to cut abrasive materials
50 TECHNICAL INFORMATION
SAFETY ADVICE
SAFETY DOs
For your safety you should ensure that you are fully aware of how to safely use diamond blades
✓ DO Read the safety instructions provided by the abrasives & equipment supplier
Examine all products before mounting & periodically during blade use for possible
✓ DO
defects or damage (core flatness, fatigue cracks, undercutting, arbor hole damage...)
Check that correct mounting devices are used & that they are clean, undistorted and free
✓ DO
from burrs
✓ DO Always use a correctly designed & adjusted guard (on the blade and belts)
✓ DO Avoid clogging & uneven wear to ensure that the product is working efficiently
Ensure that all machines using abrasives meet the requirements of the current European
✓ DO
machinery directives-CE
Be aware of the hazards likely during the use of abrasives & observe the
recommended precautions to be taken:
• Bodily contact with the abrasive product at operating speed
• Injury resulting from product breakage during use
✓ DO
• Grinding debris, sparks, fumes & dust generated by the grinding process
• Noise
• Vibration
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 51
SAFETY DON’Ts
For your safety you should ensure that you are fully aware of how to safely use diamond blades
✘ DON’T Use a product that is damaged or one which has been dropped
✘ DON’T Use a machine that is not in good working order or one with defective parts
✘ DON’T Force the abrasive onto the mounting device or modify the size of the mounting hole
✘ DON’T Use mounting flanges which are not clean & flat
✘ DON’T Start the machine until the guard is in place & fastened securely
✘ DON’T Grind on the part of the product which is not designed for the operation
✘ DON’T Start the machine with the workpiece in contact with the abrasive product
✘ DON’T Stop the abrasive by applying pressure to its surface, let it stop naturally
52 TECHNICAL INFORMATION
NOTES
INFORMATION
TECHNICAL
TECHNICAL INFORMATION 53
NOTES
INFORMATION
TECHNICAL
54 TECHNICAL INFORMATION