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cut-off wheels

What is an Abrasive Cut Off Wheel?

Cutting wheels are an abrasive tool used for fast cutting and grinding of materials like metal, concrete, and stone.  Their portability allows the operator to move around freely with it and maneuver the disc from different angles to easily cut a material.

Cutoff wheels for angle grinders are the most commonly used option, but different wheels are compatible with die grinders, air cut off tools, electric cut off tools, chop saws, circular saws, and gas saws.  They are often used to quickly cut pipes, rusted bolts, metal fabrication, and cutting through auto body panels.

What are Cutting Wheels Made Of?

High-quality cutting discs are made of resinoid-bonded abrasives.  The bonding agent, resinoid, holds the wheel and the abrasive material together.  As it wears away through use, fresh sharp grains are exposed to continue cutting.

The most commonly used abrasives embedded in the resinoid wheels are aluminum oxide and silicon carbide.  

Reinforced cutoff wheels are the most durable cut wheels.  They are reinforced with fiberglass to provide extra strength to last long and avoid breaking from extra pressure forced on it.

Cutting Disc Types

Besides the overall size of the cut-off discs, the main differences to consider are T1 vs T27 types and thickness.

Type 1 vs Type 27 Cut Off Wheels

Type 1 (T1) wheels are flat across the entire face, from the edges through the center, of the cutting disc.  

Type 27 (T27) cut wheels are also flat, but the center of the disc is pushed back.  This “depressed center” feature allows you to use the wheel without interference from the flange/lock nut center connection.  This helps allow you to get closer to a surface and get a more flush cut.  For example, cutting a bolt would be difficult with a T1 disc because the flange from a grinder will force a space, making it impossible to cut it from a 90-degree angle.

Thickness

Ultra-thin cut-off wheels are 0.04” and 0.045” thick.  These thinner discs are the best cut-off wheels for metal when you want a faster cut with less material waste. Thicker cutting wheels will remove more metal, but are the longest lasting cutoff wheels and don’t require rocking the wheel back and forth as much to make a cut.

Cut Off Wheels for Aluminum Cutting

Aluminum is a soft metal with a low melting point.  This means that with the wrong tools, you can damage the metal or cause extra work caused by burr formation.  The best cut-off wheels for aluminum avoid load by using abrasives that remain cooler to avoid this.  An aluminum cutting disc with a special formulation of aluminum oxide and silicon carbide can be used for cutting aluminum and other soft metals like brass, bronze, copper, and other non-ferrous soft metals.

What is the Difference Between Cutoff Wheels and Grinding Wheels?

Cutting wheels and grinding wheels are similar in construction, both using resinoid bonded abrasives.  Both cutoff discs and grinding discs are also available in T1 and T27 types.  The difference between the two is the thickness of the wheels which affects their application.

Cutoff discs thickness range from 0.04” to 3/32” while the thicker grinding discs range from 1/8" to 1/4".  The thickness of grinding wheels makes them much sturdier so you can grind a surface from different angles.  Using a cutting disc to aggressively grind metal is dangerous and risks breaking the wheels at a high RPM.