Grinding wheels are among the most commonly used of all grinding abrasives out there, and are frequently used to remove stock material from a workpiece, or else to profile or reshape it.
That being said, there are many different types of grinding wheels made with different grinding abrasives, some of which are suitable for some materials and applications, and some which are not so much. This post will break some of that down from a high level.
Grinding Abrasive Selection
Grinding wheels are impregnated with different types of grinding abrasives, each of which has its own unique properties in terms of hardness, resistance to impact, general toughness, and fracture resistance as well, among others. Here are some of the more common types.
- Aluminum oxide. This is one of the most common of all grinding abrasives, and many different grits of sandpaper, not just grinding wheels, are made with chips of aluminum oxide that serve as a grinding abrasive to cut away material. There are many different grades of aluminum oxide, designated by manufacturer, but nonetheless, this grinding abrasive is commonly used on workpieces made of materials such as carbon steel, high speed steel, other steel alloys, wrought iron, annealed iron, bronze, and other metals. Sandpaper made with aluminum oxide is also a common abrasive for sanding wood
- Zirconia alumina. This is another common grinding abrasive, which like aluminum oxide is available in different grades. Regardless, it is commonly used in rough grinding applications. It is commonly used in cut-off wheels and used to cut steel.
- Silicon carbide. Silicon carbide is a very hard grinding abrasive that is often used when working with a wide range of workpiece materials beyond metals. It is commonly used to grind or cut chilled iron, bronze, brass, aluminum, and other materials like stone and nonferrous material.
- Ceramic aluminum oxide. This is a newer class of grinding abrasive, which is produced using a gel sintering process. It is a very hard and strong grinding abrasive with a unique property; it fractures at the sub-micron level, which constantly creates new cutting points as the abrasive is used. In other words, it “self-maintains” as it is used, rather than getting “dull” and so is able to maintain its grinding efficiency. It is commonly used when working with steel and other metal alloys that are conventionally difficult to grind.
Grain and Grit Size
Grinding abrasives are composed of many fine grains, often in one of the materials mentioned in the last section. The grains are classed according to grit size, which indicates how large they are and how aggressively they will remove material.
Lower grit indicates a coarser grain size, and lower grit grinding abrasives will be more effective at quickly removing stock material from a workpiece, especially when run at higher speeds.
Conversely, a higher grit indicates a finer grain size. Finer grit is not necessarily more effective at grinding or cutting, but it can be used in some wheels for finishing and polishing, depending on what the grit classification actually is.
Explore Grinding Abrasives Online at TMT Toolbox
Want to learn more about grinding abrasives or simply replace some cut-off wheels from your shop? Visit TMT Toolbox. They carry a wide range of grinding abrasives, machine tools, and accessories, at competitive prices, and have a customer service team that is ready and willing to help.
Whether you have questions or are ready to buy, visit their website or get in touch with them for more information.
For more information about Milling Inserts and Machinist Tools And Supplies Please visit: TMT Toolbox.
