The Basics of Cutting Wheels
transfer from https://www.thefabricator.com/article/cuttingweldprep/cutting-metal-with-cutting-wheels
The main considerations in using resinoid-bonded wheels include the cutting application, the tool being used—such as a right-angle grinder, die grinder, or chop saw—desired cutting action, the material being cut, and space. Wheels typically provide a fast cutting action, long life, and tend to be cost-effective.
The two main types of resinoid-bonded abrasive cutting wheels are Type 1, which are flat, and Type 27, which have a raised hub. Type 1 wheels generally are used for straight-on cutting on electric or pneumatic right-angle grinders or die grinders and chop saws, among other tools. Type 27 wheels are required when there is some type of interference and the wheel needs to be raised up from the base of the grinder, but personal preference also plays a role in the decision. They are most commonly used with electric or pneumatic right-angle grinders.
Resinoid-bonded abrasive cutting wheels are available in various sizes and thicknesses. The most popular range is 2 to 16 inches in diameter, and common thicknesses are from 0.045 in. to 1⁄8 in. Thinner wheels remove less material during the cut.
Some types of wheels cut faster than others. The abrasive material used in the wheel is one influencer on cut rate and consumable life. Wheels come in several grain options, such as aluminum oxide, silicon carbide, zirconia alumina, ceramic alumina, and combinations of these materials.
While not as sharp as other grains, aluminum oxide provides toughness and good performance for cutting on steel. Silicon carbide, on the other hand, is a very sharp grain but not quite as tough, making it suitable for cutting nonferrous metals. Zirconia alumina is a self-sharpening, tough, durable grain that holds up well in a range of demanding applications. Ceramic alumina also is designed to self-sharpen as it “breaks” at predetermined points to maintain a consistent cut rate and long life.
When selecting a resinoid-bonded abrasive wheel, consider that products made with a mixture of zirconia or ceramic alumina with a harder bond typically cost more but offer durability and longer consumable life.
Make sure to refer to the manufacturer’s recommendations, product descriptions, and RPM ratings to select the proper wheel size and bonded abrasive material for your application. Matching the size and RPM rating of the tool to the size and RPM rating of the wheel is critical for safe and effective usage. Choosing the tool with the greatest amperage or amount of torque while staying within size and RPM requirements of the wheel will increase performance.
The kind of tool and the tool guard that you use also are factors that play a role in the type of wheel that can be used for an application. A larger-diameter wheel works best if you’re cutting deep into metal or need to cut a piece with a large diameter, for example, because it eliminates the need to rock the wheel back and forth during the cutting process. Look for a wheel with the diameter designed for the size and thickness of material being cut.
Thin wheels, on the other hand, tend to remove less metal during the cut and have shorter life spans, but provide a quicker cut. There are some exceptions to this as different versions of thin wheels are lasting longer, so be sure to do your research before you make a final decision to ensure the wheel you select maximizes efficiency.
Specialty cutting wheels are also available that are designed for use with certain materials, such as stainless steel and aluminum.