DIN-58405-3-1972 Spur Gear Drives For Fine Mechanics - Indication in Drawings, Examples For Calculation PDF
DIN-58405-3-1972 Spur Gear Drives For Fine Mechanics - Indication in Drawings, Examples For Calculation PDF
DIN-58405-3-1972 Spur Gear Drives For Fine Mechanics - Indication in Drawings, Examples For Calculation PDF
The references to the other Sheets of this Standard relate to the b y 1972 issues.
Dimensions in mm
------------------ ---------
1.1. Data for the gear blank
-_
I.
1. dem neuesten Ausgabedatum. Vergewissern Sie ?
1.
1.
II sich bitte in den DIN-Mitteilungen, im .aktuellen
1.
1.
DI
DIN-Katalog mit dem neuesten Ergnzungsheft
1.
W oder in der aktuellen Ausgabe der PERINORM.
1.
II
I.
YTA " -
A._& "
--
.
-.
y
In the case of straight spur gears a horizontal stroke is indicated. In a drive with extemuillg
toothed helical spur gears, one gear of the pair is always right-handed and the other left-
handed.
Continued on pages 2 to 19
lleinverkauf der Normbltter durch Beuth-Vertrieb GmbH, Berlin 30 und Kln DIH 58405 B1.3 engl. Preisgr.'
DC 621.833 : 681 DEUTSCHE NORMEN h y 1972
The references to the other Sheets of this Standard relate to the b y 1972 issues.
Dimensions in mm
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
------------------ ---------
1.1. Data f o r the gear blank
Left 0 left-handed
In the case of straight spur gears a horizontal stroke is indicated. In a drive with extemuillg
toothed helical spur gears, one gear of the pair is always right-handed and the other left-
handed.
Continued on pages 2 to 19
einverkauf der Normbltter durch Beuth-Vertrieb GmbH, Berlin 30 und Kln DIN 58405 B1.3 engl. Preisgr.'
Page 2 D I N 58405 Sheet 3
1.2.9. f i t G e a r
a c c o r d i n g
58405 Sheet 2 t o Dm
"he p a r t i c u l a r s t o be i n d i c a t e d a r e t h e geaI
f i t s e l e c t e d according t o DIN 58405 Sheet 1,
Section 4, i n conjunction w i t h DI 58405
Sheet 2, S e c t i o n 1, and a l s o t h e symbol f o r
t h e s p e c i f i e d acceptance t e s t i n g (e.g. Number of t e e t h
7 J/7 f S").
1.2.10. P e r m i s s i b 1e
e r r o r r a n g e
t o t a 1
Ff
Module m l I
Depending on t h e g e a r f i t s e l e c t e d , t h e t o t a Pitch c i r c l e diameter dn I I
e r r o r range according t o D I N 58405 Sheet 2,
Section 6, permitted f o r t h e Rear - should be Basic rack p r o f i l e IDIN I
entered. Addendum modification f a c t o r x
For V t o o t h systems t h e t o t a l e r r o r range I'$
obtained from S e c t i o n 6 could i f necessary b Helix angle fi0
multi l i e d by t h e f a c t o r L according t o equa
t i o n p51) Sheet 2. Face alignment
1.2.11. P e r m i s s i b 1e t o o t h
t o t o o t h c o m p o s i t e
e r r o r fp
Depending on t h e g e a r f i t s e l e c t e d , t h e t o o t
t o t o o t h composite e r r o r according t o
DIN 58405 Sheet 2, S e c t i o n 6, permitted f o r
t h e g e a r should be entered.
In t h e case of V t o o t h systems t h e t o o t h t o Dual cone width I I
t o o t h composite e r r o r f i obtained from Sec- Centre distance i n the
t i o n 6 should i f necessary be m u l t i p l i e d by dual flank r o l l t e s t e r
t h e f a c t o r L according t o equation (51) with master gear
Sheet 2.
1.2.12. P e r m i s s i b l e f a c e Number of mating gear
a l i g n m e n t e r r o r
Depending on t h e g e a r f i t s e l e c t e d , t h e f Centre distance i n housing a I I
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
I
permissible f a c e alignment e r r o r according Base tangent length =
t o DIB.58405 Sheet 2 , S e c t i o n 6, should be
entered. almeasured over z' = Teeth
1.2.13. D u a l c o n e w i d t h N
The dimension entered a s t h e dual cone width
i s t h e nominal dimension N according t o
b)measured indirectly over t i p c i r c l e
1
DIN 58405 Sheet I , S e c t i o n 3.5, D l U S t h e Figure 2. Gearcutting t a b l e
upper dual cone width allowance according
t o D I N 58405 Sheet 2, S e c t i o n 6, corresponding t o t h e g e a r f i t selected. The d i f f e r e n c e
between t h e upper and t h e lower dual cone width allowance i s appended a s a minus v a r i a t i o n .
Exampl e :
Nominal dimension of dual cone width N = 30.845
Upper dual cone width allowance ANO = -0.078
Lower dual cone width allowance AN^ = -0.064
The dual cone width t o be entered i s t h e r e f o r e : 30.807 - 0.026.
1.2.14. C e n t r e d i s t a n c e a" i n t h e d u a l f l a n k r o l l
t e s t e r w i t h m a s t e r g e a r
Upper l i n e
The dimension entered i s t h e nominal dimension a " according t o equation (40) or (41) i n
D I N 58405 Sheet 2 p l u s t h e upper allowance on t h e dual f l a n k roll t e s t d i s t a n c e according t o
equation (42) or (44) from S e c t i o n 4.1 or equation (47) or (49) from Section 4.2. The d i f f e r -
ence between t h e upper and lower allowances of t h e dual f l a n k r o l l t e s t d i s t a n c e is appended
as a minus v a r i a t i o n . I n p r i n c i p l e t h e example i n S e c t i o n 1.2.13 applies.
Lower l i n e
D e s i m a t i o n of t h e master Rear.
1.2.75. N u m b e r of- m a t i n g e a r
The drawing number of t h e mating g e a r i s entered. I f t h e spur gear i s t o be p a i r e d with sever-
a l d i f f e r e n t mation Rears, c a r e should be taken t o ensure t h a t t h e matina - -Rears a l s o have t h e
same t o l e r a n c e zones-and grades a s t h e spur gear.
1.2.16. C e n t r e A i s t a n c e i n h o u s i n g a
The c e n t r e d i s t a n c e a according t o equation (5) i n DIN 58405 Sheet 1 and t h e allowances Aa0
and AaU according t o D I N 58405 Sheet 2, S e c t i o n 6, should be entered according t o t h e g e a r
f i t selected.
1.2.17. B a s e t a n g e n t l e n g t h W
"he dimension entered a s t h e b a s e tangent l e n g t h i s t h e nominal dimension W according t o
D I N 58405 Sheet 1, S e c t i o n 3.4, plus t h e upper base tangent l e n g t h allowance according t o
DIN 58405 Sheet 2, S e c t i o n 6, according t o t h e gear f i t selected. The d i f f e r e n c e between t h e
upper and t h e l o u e r base tangent l e n g t h allowance i s appended as a minus v a r i a t i o n .
I n p r i n c i p l e t h e example in S e c t i o n 1.2.13 applies.
The number of t e e t h e ' over which t h e base tangent l e n g t h i s measured i s obtained from t h e
Tables i n D I N 58405 Sheet 4. I f , i n t h e case of topped spur g e a r s ( t o o l b a s i c rack p r o f i l e s U 1
or U according t o D I N 58412) t h e base tangent l e n g t h i s t o be measured i n d i r e c t l y over t h e t i p
c i r c l e , t h e dimension obtained from equation (34) i n D I N 58405 Sheet 1 should be entered i n
t h e l a s t l i n e of t h e Table.
For a spur g e a r , however, m l y t h e d a t a f o r t h e d i r e c t or t h e i n d i r e c t method may be entered.
2. I n d i c a t i o n s in t h e housinu drawinq
"he dimension i n d i c a t e d i n t h e drawing i s t h e nominal dimension a c a l c u l a t e d according t o
equation (5) i n D I N 58405 Sheet 1 p l u s t h e allowances Bao and Bau according t o DIN 58405
following p a r t i c u l a r s a r e s t a t e d : Centre Tolerance zone Permissible er-
......................
2.1. Centre d i s t a n c e a distance according to
DIN 58405 Sheet
ror in axial
The nominal dimension of t h e c e n t r e d i s t a n c e i s
entered.
a and centre dis-
tance allowances
' parallelism f
ref. to 100 u&
length of axis
---
____________________------------_-----
2.2. Grade and t o l e r a n c e zone according t o
20.592 8J 0.032 _+ O,028
______________________------------_--
DIN 58405 Sheet 2 and c e n t r e d i s t a n c e
___-____
allowance -
The symbol f o r t h e allowances of t h e c e n t r e
d i s t a n c e corresponding t o t h e g e a r f i t s e l e c t e d
(e.g. 8 J ) i s s t a t e d , p l u s t h e numerical value
o f t h e allowances t o g e t h e r with any t o l e r a n c e
\ \
k
earing seating
Figure 5. Gear s h a f t with r o l l i n g bearings Figure 6. Gear s h a f t with p l a i n bearings and
intermediate bush
4. Individual e r r o r s
F u r t h e r i n d i v i d u a l errors, t h e v a l u e s of which a r e required t o be l i m i t e d , should a l s o be
l i s t e d i n t h e drawings t o g e t h e r with t h e i r symbols and permissible l i m i t i n g values.
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
Page 4 DN 58405 Shekt 3
5. &les for c a l c u l a t i o n , I n t e r m ed i a t e
For the examples below t h e c a l c u l a t i o n proforma bush
according to DIN 58405 Supplementary Sheet 1 has ,Shaft
been used.
For c l e a r e r d i f f e r e n t i a t i o n , p a r t i c u l a r s concern-
i n g the examples a r e p r i n t e d i n red.
Gear 2
--------- .................... __-----_____-
5.1. Design c a l c u l a t i o n for a g e a r d r i v e f o r
------ .....................................
s e t t i n g t h e counter mechanism of an e l e c t r o -
mecoanicai-oe1ice
I. Given
for gear 1
1.1. Speed n1
1.2. & t i o i
-
- 2
40 'J/min
Gear '-'i,
,
- 1 - 1 -
2.4.1. H e l i x angle o - 112.4 O - l o
2.5. Basic rack p r o f i l e of
t o o l according t o
- - U I topping
N = non-topping
- D I N 58412
2.6. Material 2/1 -
2.7.
- Face w i d t h b - I 112.7 I
2.8. Basic rack p r o f i l e - 112.1 I
3 . Calculated d a t a
32. 113.2.1
3.2.1. To a v o i d u n d e r c u t t i n g i / Fig. 113.2.3 "gT - =
1 4 a.5 x = (Y, + AY,) ___
'IT
:
3.2.2. To y i e l d e x i s t i n g
centre d i s t a n c e a
llequa-
t ions
x1 + 22 = (evab, - evao,) x
according t o 1.5 1 5 ) t O (91 z1 + z2
X
2 tan aon
abs from:
m" 21 + "2
cosab, -e-=
cospe 2
cos aop
X-
a
aosfrom:
tanaon
tan ao6 = ~
cos Bn
."
making sure t h a t no under-
c u t t i n g is thereby introduced
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
DIN 58405 Sheet 3 Page 5
3.3.
(tip easing possibly
3.4.
needed in the event of
addendum modification
according to 3.2)
Centre distance a
- ip.1.1
di, = d ~ + Z m , ( z + y ) - Z k m ,
I I
25'1 49*1
cos aor,
'or -
cos ab
see DIN 58405 Sheet 4,
iection 2
T-
Dual cone width A N O Section 1.2.17 or 1.2.13
4.1.8. allowances Plfrom should be entered in the
2/45
ANu
Sect. 6 drawing. -
4.1.9. Allowances Adk of tip
circle diameter with
- 213.1
indirect base tangent
length measurement
(only for topped spur 1."
gears)
The tip circle diameter d'
according to equation (349
should be entered in the
drawing.
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
Page 6 D W 58405 Sheet 3
y
Dual flank roll ABo
tester centre ~
Bearing
Permissible radial 211.2 d for gear 2 : IS0
clearance SL clearance fit H51g5; @ t
Dimensional, geometrical
and running accuracy
for gear 2:
Permissible radial run- Eccentricity of seatings
out of rolling bearing on shaft
outer ring frL
Housing
Centre distance allow-
ancee
* a o and '
a
u
1I
2 / fro
;ect. 6
215.1 When rolling bearings and
insert plain bearings are
used, equations (52) and
(53) should be applied.
HH-I
IS0 tolerance zone of f o r gear 2:
bearing bores IS0 tolerance zone o f
2" 211-2c a x i a l bore
Permissible error in
axial parallelism f 28
P
2. Check calculation
113.6
'dmSi=
'd max + 'd
2
d' m i r - 'd
min
*I
min
f 0,6 n
L
re 3.3.
dki = 2 5 , l mm d ~ =2 49,l mm
re 3.4.
re 4.1.2.
re 4.1.10.
II 24 + 3 8
a
1- 2
a, = 31 mm
re 4.2.1. Shaft 1: Seatings for gear and bearing ground overall, hence only the radial run-out of the
rolling bearing inner ring ( I O pm PO 2 , see 4.3.2) is effective.
Shaft 2 : Only the running and intermediate bushes belong to shaft 2.
Ti3 = 64 - 15 - 6
T B = 43 piii
I I
f ,i = t 22 pm
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
page 8 DIN 58405 Sheet 3
24
0.5 I Number of t e e t h
Module
P i t c h c i r c l e diameter d0 48
0.5
~
Gear f i t t o D I N 58405
43
I
I 8Ji8f
o
- II H e l i x angle
Face alignment
Gear f i t t o D I N 58405
00
8.1 18f
0
-
Base tangent
length - 16.1 4 8 ~ 0 , o -
0 ) measured over z' 1 1 teeth
b)measured i n d i r e c t l y over t i p c i r c l e
I b) measured i n d i r e c t l y over t i n c i r c l e I
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
DIN 5 M 5 Sheet 3 Page 9
5.2. De S i~-caic~ia4,ioo_fo~-~-~~~~~~~~~~oa~-~~~~~-~~~
---------------
a servo rrontrol -Gear 2
I.Given
for gear I
1.1. Speed n l I 4000 U/min
1.2. Ratio i I 3.125
I. 3. Mean torsional backlash Sdm I 00 6 '
-Interme!diate
referred t o the large gear bush
1.4. MaxMum torsional backlash Sa Ip8x .
I '0 10'
referred t o the large gear
1.5. Existing centre distance a 0 41.400 ITIIU
2. Conditions s e l e c t e d
2.1.
2.2.
2.3.
2.4.
2.4.1.
2.5.
2.6.
2.7.
2.8.
3. Calculated data
-
Pitch c i r c l e diameter dg 19,877 62,116 mm
-
Addendum modification
x - mn - I1/3.2.1 0,240 0,176 mm
32.1. T o avoid undercutting 11 Fig.4 lp.2.3
and 5 f: = (Yw + AYw)-----
ZgT -=
Po y i e l d e x i s t i n g - i/equa- X I + x2 = (evabs - evao,) x
centre distance a t ions
according t o 1.5 21 + 22 -t 0.300 t 02?0
(5) t o (91 X
2 tan ao,,
aba from:
mn 21 + 22
cosaha = 1
--
coso 2
cos aoe
X-
a
aOe from:
tan ao,,
tanaOs = ~
cos Bo
laking 8ure that no under-
:utting is thereby introduced
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
Page IO D I N 58405 Sheet 3
3.4. Centre d i s t a n c e a
41.400 mm
cos "0,
?or -
cos abs
3ee D I N 58405 Sheet 4,
section 2
-
3.5. Base tangent l e n g t h W 411 113.4 W=w'+AW mm
AW = 2 x . mn sin aOn
for setting
I
4.1.10. Centre d i s t a n c e a" i n
I
1
-
DIN 58405
Sheet/ p
Table
- 1
t /
ection
2/4.1 Equation
Equation
or remarks
4.2. Shaft
42.1. Permissible r a d i a l run-
o u t frw
2/1 3/3 ~ ~ t ~ bm ~ ~s ~ d~ ~Q ia ~ ~ 12~~ o r 16 Iim
rolling bearing i n n e r r i n g s
present
4.2.2. IS0 grade of s e a t i n g 2/1 3/3 ~ ~ , " ~ ~ 5 ~-
diameters of gear and
t i o n 1.2 c
5 5
bearing bearing
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
4.3. Bearkg
4.4. Rousing
~
1
4.4.1. Centre d i s t a n c e allow- 21 fro 2/51 When r o l l i n g bearings and
ances Sect. 6 i n s e r t p l a i n bearings are
Aa, rndA.3" used, equations (52) and
(53) should be applied.
7
4.4.3. Permissible e r r o r i n 21from 2/52 17 IJm
axia parallelism f Sect. 6
P
21 - 0,8 75 .0,8
r e 3.1. d o , = -- d o , = ~-
0.965 93 0,965 93
d o l = 19,877 mm d o , = 62,116 mm
Page 12 DIN 58405 Sheet 3
~
0,363 97 ah = ~. O,$ 24 + 75
~. 0,93575
r e 3.2.2. tan aoe ~
0,965 93 2 41,400
~
0,965 93
t a n aos= 0,37680 C O 6 n h s = 0,92663
(20,2918 - 16,4611).
24 + 75
z1 4- 2 2 2 .O,363 97
x1 f x2 = 0,52
r e 3.1.
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
AWi =z 2 .0,3 . 0,8 .0,342 02 3w2 = 2 8,22 0,8 0,342 02
Awl = 0,1642 AW, = 0,1204
W, = 8,5628 0,1642 W 2 = 23,3639 + 0,1204
W, - 8,727 mni W? = 23,484 IIIICI
al=---'-
19,877 +2 62.945 0.93571
0,92742
o
'2
.1 62 116 _
= 62.945 i +
0,93571 -..-
2 0,9354
= 41.693 mm ai = 62,649 mm
~__________
-
Ain:=
0.5321
-__ [(-
0,37746
23) + (- 2)]
*e 4.2.1. f o r g e a r 1: fcr g e a r 2 :
bearing seating 8,5 bearing seating 4.0
bearing inner 3,5 bearing inner r i n g 3,5
ring s e a t i n g f o r interme- 4,O
12.0 pin
d i a t e bush
intermediate bush 45
16,O pm
-~
DIN 58405 Sheet 3 Page 1 3
r .
r e 4.4.1. l a = I 20 ( 20) T"+40 5 - 5
r e 5 1. = + 40 Itm + 30 pm Tg 2 ? 15 vrn
T o r s i o n a l backlash with absolute t o l e r a n c e a d d i t i o n :
1,064
Sdlnax - - [( ~ 28) i( - 38)] __- -t 2 . 1 5 . 0 , 4 0 5 7 2
0,96593
S,jmax = 85 piil
_
["I
referred t o the large S<lrnin= 41296
cear: 62,116
s,,
Y
iiiiii = 3'30"
S,I ni = -
+
,
9'24" 3':10"
Sd st = ~~
84.97 + 31,93 81 9; - .
0.6 Ap-l!~':- 0 ."
4
2 -
.S(, ';, = 58 f 27 U n i
.,-
* 1-12.6.--d-
~
Sdmox
62,116
= 11'12"
i"1
40.9967
cos al,* = - .0,935 75
41,400 - 0,020 - 0,006 - 0.008 - 0,0035 - 0,0035
Silinin == 17 yrn
r e f e r r e d t o t h e large
gear:
S d n i i i=
i 412,6
SIIIrlili = 1'12'(
62,116 ['I
_ _ _ ~
s,, =
11'1.2" + 1'12"
2
= 6'27"
~
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
Page 1 4 D M 58405 Sheet 3
I'
~. 3.14. 0,93571
0.965 93
= 10.
0,26795 0,96593
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
t ~~~
RP 0.8 . 3,14
7. Summan
11 1 2
Gear 2;
Gear Drawing number Drawing number
2-30 Desigo-calcoatioo-ooE_a-~o~~-~~~~-~~i~~-~~~-~~~
-_------
with a s p-----------------
c h r o transmitter
I.Given -Gear 2
for g e a r 1
1.1. Speed nl = 100 /min
1.2. Ratio i 1 5
I. J. Mean t o r s i o n a l backlash Sdm P -
r e f e r r e d t o t h e l a r g e gear
1.4. Maximum t o r s i o n a l backlash Sa max = go 8 '
referred t o the large gear
1.5. B i s t i n g c e n t r e d i s t a n c e a I -
Gear 1
2. Conditions s e l e c t e d
2.5.
2.6.
Basic rack profile of
tool according to
DIN 58412
Material
I - -- 1
2/1
I
U = topping
N non-topping
I
37 MnSi 37 MnSi -
5v 5Y
27. Face width b I - I 1p-7 I I 4 I 3 Imm
28. Basic rack profile I - 1 1/2.i I I DIN 58400 1 -
Calculated d a t a
I
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
CO8 ao ~
X-
a
aos from:
tan mon
tan aos = -
cos Bo
making sure that no under-
cutting is thereby introduce,
Page 16 DIN 58405 Shhet 3
-
19,355 rnm
cos ao#
hen 21 and 2 2 =o , -- -1
cos a b m
cos ao*
D r
cosab,
~
ee Table 2 i n Sheet 4
i n d i r e c t base tangent
l e n g t h measurement
(only f o r topped spur
gears) - 23 - 35
The t i p c i r c l e diameter dk
according t o equation (34)
should be e n t e r e d i n t h e
drawing.
--
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
D I N 58405 Sheet 3 Page 17
DIN 1405
Equation
Sheet/ Sheet/ o r remark6
Table iection
:entre d i s t a n c e a" i n 214.1
9ual f l a n k r o l l t e s t e r or
d i t h master gear 4.2
Dual f l a n k r o l l AB, Equation (42) t o ( 4 5 ) or (47)
tester centre - to ( 5 0 )
distance allow- APU
=ces
Shaft
Permissible r a i a l run- 313
out fFW bearing i n n e r r i n g s
~~
Bearing
Permissible r a d i a l 211.2 d
clearance SL
Dimensional, geometrical 211
and running accuracy
-
-
Permissible r a d i a l run-
out of r o l l i n g bearing
o u t e r r i n g frL
Housing
I I I V rn
,a
Permissible e r r o r i n
axial parallelism f
P
Z/fron
Sect.
2/52 1%
I *m
5. Check calculations
r e 3.2.1.
re 3.3. 2.0,36397-0,4 +
e , abs =
and 3.4. 16 80 +
e* = 0,017 937 5 mm
ao =
6,L. ~
+ 32
2 a = 19,2. 1,008 09
ao = 19,2 mm
= 19,355 mm_
k .Inl, = 19,2 i- 0 , 4 . 0,4 - 19,355
Ir ' rrlII = 0,005 m111
.
d k l = 6,4 f 2 0,4 (0,4f 1 , l ) - 2 . 0,005 d,, - 32 + 2 . 0,4. 1,1
d, 1 ;= 7,590 111111 dk2 E 32,880 mm
~
re 4.1.2.
-- 8.5~
- 0,34202
- -
I + 5 pn
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
- 13 +5 - 17 5
~ rn+ Adhi~2 ~
0,342 O2
t __-
0,363 97
re 4.1.10
= 21,756 min
re 4.4.1.
DIN 58405 Sheet 3 page 19
r e 5.1.
--``,`,,`,,```,,`,`,,,``,```,`-`-`,,`,,`,`,,`---
t =2,0
P
7. Summary
Gear 1 ;
c1 c2
Gear 2 ;
Drawing number
a ooa
Li-I\ aoos
2, Applies t o t h e machining of t h e blank.