User talk:Diamond-blades

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Master Blade International

Email: diamondblades@masterblade.net

¿WHAT IS A DIAMOND BLADE?

File:Diamond Blade-Asphalt-over-Concrete-www.MasterBlade.net-BlackTop-Pro.jpg

A DIAMOND BLADE is a circular blade for cutting a wide variety of materiales with special cutting equipment. It is made up of a STEEL CORE containing special Diamond Segments. There are several different types of segments: Segmented, Continuous Rim, Turbo (Serrated Continuous Rim), Turbo Segmented Blade (with serrated segments).

The core of the blade is made of precision steel and may have several gullets (spaces between segments) depending on the usage of the blade. These gullets allow a cooling process through air or water circulation between the segments. They also allow the blade to bend under high tension cutting.

The diamond segments are a mixture of diamond crystals and metallic powders. The diamonds used in the blades are sinthetic or natural industrial diamonds of several different grain sizes, shapes or qualities.

¿HOW DOES A DIAMOND BLADE CUT?

File:Diamond-Blades-www.MasterBlade.net-Diamond Blade.jpg

A diamond blade doesn't cut like a knife, it grinds. Through the fabrication process, diamond crystals are exposed on the surface and the sides of the segments. These exposed diamonds do the grinding. The bond of metal powders hold the diamonds in place throughout the cutting process. Behind each diamond crystal, there's a "tail" (like a comet) which helps hold the diamond crystals in place.

Through the cutting process, the operator will push the blade through the material. The blade will begin to cut through the material, and the material being cut will begin the wearing process of the diamond blade, at the rate of which the blade advances.

The exposed diamonds will break into smaller pieces when cutting. Hard, Dense materials will fracture the diamonds faster. As this happens, the material being cut also wears down the metal bond through abrasion. Highly abrasive materials will wear the bond faster, exposing new diamond crystals to continue cutting.

¿HOW TO SELECT A DIAMOND BLADE?

Before you begin. The contractor should decide which is more important: whether it's the initial cost of the blade or the cost per foot/meter. For smaller jobs or occasional use, you may prefer a lower priced blade. For larger more important jobs the cost per foot/meter is generally much more significant than the inicial cost of the blade.

Identify what you will be cutting. This is the single most important factor. The majority of diamond blades cut only a specific variety of materials. For more eficiency (of cutting speed and duration), you should be sure to select the best type of blade for your application.

Choosing between dry/wet cutting. Using some equipment you may not be able to use water due to electricity. For floor saws (walk behind) it is preferrable to use water to reduce dust levels and act as a coolant for the blade.

For high speed saws, dry cutting blades are recommended, however sometimes water may be used to control dust levels.

While wet cutting blades and core bits must be used ONLY with water, dry cutting blades on the other hand can be used with or without water (depending on the job situations or the equipment).

Under Cutting of Segment Supports

Cause. Under cutting is a situation in which the base of the segments wear down before the diamond segment itself. Usually right at the union of the segment & the supporting steel core.

This condition is caused by highly abrasive materials creating friction along the blade in a consistent pattern.

In general sand based materials are responsable for this situation. For example: Green Concrete, Asphalt, Prefabricated Cement (with sinthetic of fractured sand), etc.

Remedy. The distribution of the abrasive residue over a larger surface area, further away from the critical support area beneath the segments. This is usually achieved by using Under Cut Protection segments which are deeper than the rest to help change the path of the abrasive slurry and distribute it over a larger & safer area. You should also use plenty of water to eliminate the abrasive residues.

Uneven wear of the segments

Cause. The segments wear down on only one side, reducing the lateral tolerance. The common cause is a badly aligned blade or the lack of sufficient water on one side of the blade.

Remedy. Verify the alignment of the equipment. Clean the water system making sure the water is evenly distributed along the border of the flanges (blade supports). Check to make sure the pump is sending enough water evenly to both sides.

Cause. The blade is wearing down badly due to worn bearings, worn shaft, an orifice on the blade's arbor which is bigger than the shaft of the saw, dirty/damaged flanges or excessive blade wear.

Remedy. Replace the bearings or the shaft. Examine the flanges to see if they are damaged.

Cracks in the Core

Cause. Excessive cutting pressure or jamming the blade in the cut can bend the segments and crack them.

Remedy. The operator must apply moderate pressure and be sure not to turn the saw while the blade is in the cut. Try to avoid uneven surfaces when cutting.

Cause. Overheating due to lack of coolant or inappropriate use of dry cutting blades.

Remedy. Use the correct amount of water when using wet cutting blades (for example 2 to 5 gallons per minute on walkbehind saws). For high speed saws, allow them to run freely for about 15 seconds after a few minutes of cutting so the air can act as a coolant.

Cause. The metal bond of the blade is too hard for the material being cut.

Remedy. Use a blade with a softer bond.

Segment loss

Cause. The material slips during the cutting which causes the blade to jam or throw a segment.

Remedy. Make sure the material being cut is held in place correctly before cutting.

Cause. Worn flanges aren't providing enough support which causes the blade to slip.

Remedy. Replace both flanges.

Cause. Overheating. Easily detected by a bluish color underneath the segments, generally limited to the area of the lost segment.

Remedy. Check to see if the water system is being clogged. Make sure the water pump is working correctly. For dry cutting it may be necessary to cut lesser depths and allow the blade to spin freely every few minutes to allow the air to cool the blade.

Cause. Blade is too hard for the material being cut, glazing over the diamonds which causes a pounding on the material resulting in segment loss.

Remedy. Use a softer bond.

Cracked Segments

Cause. The bond is too hard for the material being cut. The hard bond retains the diamonds which are rounded off and instead of cutting, the segments become smooth and lose their cutting "edge".

Remedy. Change to a softer bond which can wear down faster, allowing new diamond crystals to be exposed to continue cutting.

Overheated blade

Cause. Lack of sufficient coolant.

Remedy. Check the water system for clogged nozzles. Use dry cutting blades only for superficial cuts (2-5 cm).

Cause. Continuing to cut with a blade which no longer has useful diamond segments.

Remedy. Always check the segments when the blade is nearly worn out. With laser welded blades there is a small laser welding pad of approximately 1mm. For example a laser welded blade with 10mm segments has approx. 9mm of useful segment heigth and should be discarded once the laser welding pad is reached. This can avoid damage and prolong the life of the saw.

Blade will not cut

Cause. The bond is too hard for the material being cut. The segments become smooth. (Example: Using an asphalt blade for cutting hard Cured Concrete)

Remedy. Consult your provider for the apropriate blade to effectively cut the material. If the segments become smooth and no longer cut, you can re-sharpen the segments by cutting an abrasive material such as asphalt or cinderblock until the segments are rough once again.

Info Provided by: Master Blade International www.MasterBlade.net