How to Choose a Diamond Blade

Here is some information to help you choose the right diamond blade for you and your business.


Material

The type of material you're cutting is the key to determining the best diamond blade for your needs.

Cured Concrete: If you plan to cut cured concrete without water, it's best to shop for a laser-welded blade. The laser welding process is the strongest process available for attaching cutting segments to steel blade cores, thus reducing problems associated with segment loss. It's best to find a company that provides a life time warranty on their products. This way, you're covered from financial loss if the blade becomes damaged and unusable before it wears out.

If you plan to run the blade with water, you can use a sintered saw blade. However, if the concrete contains reinforcement, you'll want to use to a laser-welded saw blade instead.

You may also want to consider buying a laser-welded turbo segmented blade if you know that you’ll be cutting reinforced concrete. A turbo segmented blade will cut faster through reinforced concrete.

For jobs with lots of prolonged concrete cutting, it's best to find a supplier who can match your blade’s bond with your concrete aggregate. You should also take into consideration whether your concrete will have rebar or wire mesh reinforcement. Matching your blade's bond to your aggregate will give you a fast cutting blade with a satisfying life.

The hardness of concrete aggregate varies depending on the part of the country that you’re in. Luckily, concrete is often locally produced, so you can determine the hardness of your aggregate by where your job is.


This aggregate map can help you determine your aggregate hardness. For example, someone cutting in Louisiana would need a blade with a soft bond to maximize cutting speed and blade life in concrete with hard aggregate. Someone in Florida, on the other hand, would need a blade with a harder bond for cutting concrete with soft aggregate.

This aggregate map can help you determine your aggregate hardness. For example, someone cutting in Louisiana would need a blade with a soft bond to maximize cutting speed and blade life in concrete with hard aggregate. Someone in Florida, on the other hand, would need a blade with a harder bond for cutting concrete with soft aggregate.


Asphalt and Green Concrete: Asphalt and green concrete are softer and more abrasive than cured concrete. For these materials, it's best to shop for a blade with a hard bond.

If you dry cut, you'll want to choose a laser-welded blade to prevent segment loss. You'll also want a blade that has either drop segments or carbide inserts to protect against undercutting. On the other hand, if you plan to use the blade with water, you can go with a hard-bonded sintered blade. You usually don't need to worry about hitting rebar when cutting asphalt. Stranger things have happened, though, so be careful.

As with concrete cutting, if you find yourself doing lots of asphalt cutting, it's best to find a supplier that can match your blade bond to the type of asphalt aggregate you're dealing with. This way, you get optimal cutting speed and maximum blade life.

For green concrete, it's best to look for a blade that's a little bit thinner than 0.125”, the standard blade thickness. By using a 0.100” or 0.110” thick blade in fresh concrete, you'll reduce spalling problems and also prevent any cracking or chipping that may occur.

Pipe: When shopping for an underground pipe cutting blade, it's best to find a blade that can handle any type of pipe. Pipe materials include, but are not limited to, ductile iron, cast iron, PVC, HDPE, AC, RCP, clay and ceramic. The Safety Blade (see pages 1 and 4) is your best option here, because it can cut all of these materials and more without any trouble.

In addition, if you have to bevel pipe occasionally, you can use the side of the Safety Blade’s 8mm cutting surface. This provides optimal beveling capabilities when using the side of the cutting edge. Do not bevel with abrasive, welded or sintered blades. They’ll shatter or lose segments and possibly injure or kill you if you use them to bevel.

It's best to find a supplier that offers a Life Time Operator Error Warranty™ on their products. This way, if the blade is damaged from getting pinched in the pipe, you're covered against any financial loss.

Masonry and Landscape: The masonry and landscape industry uses a wide variety of material like brick, block, granite, stone and pavers. Each of these materials has an assortment of densities and other qualities that affect cutting speed and blade life.

Generally speaking, if you want a good multi-purpose blade that can tackle most industry-standard materials, you'll want a blade with a medium-soft bond. On the other hand, you'll want a hard-bonded blade if you cut lots of softer and/or abrasive materials like block and sandstone and a soft-bonded blade if you cut lots of hard, dense and/or non-abrasive materials.

You can also buy blades for more specialized applications. For material that chips or cracks easily, use a continuous rim blade. For faster cutting, look for a turbo segmented blade with large gullets between the segments. To reduce cutting noise, look for a diamond blade with a sound-dampening core.


Tool

You also need to consider the type of tool you’ll be using in order to maximize your blade’s life and performance and keep yourself safe.

Handheld vs. Walk-Behind Saws: Generally speaking, if you use a walk-behind saw that is 20 HP or above, you'll need a blade that’s pre-tensioned for high speed and high torque. If you use a handheld saw blade on a high-horsepower walk-behind saw, the blade’s cutting segment will burn up in a matter of minutes, endangering your safety and possibly your life.

Stihl Saws: If you use a Stihl handheld saw, look for blades with straight 20mm arbor holes. This will help prevent problems associated with vibrating or wobbling. Not only that, but you’ll never have to worry about losing bushings.


Other Considerations

In order to get maximum blade life and lowest cost-per-cut, here are some other things you need to consider.

Diamond Concentration: A blade’s diamond concentration will determine how long it lasts. This concentration can vary from 10% to 45%. For jobs that require lots of cutting, you'll want a blade with a high diamond content. For small jobs that require little cutting, on the other hand, you can get away with a blade with a lower diamond content.

Diamond Segment Height: The height of a blade’s cutting segments will also determine its life. Segment height can vary between 3mm and 15mm.

For large cutting jobs, look for a larger diamond segment. For smaller jobs, you may be able to get away with a 3mm segment.

Wet and Dry Cutting: Using water with your diamond blades is the best way to maximize their lives. It will also give you a cleaner cut, reduce heat build-up and cut back on dust.

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