Hello and welcome to another edition of Grainger Ask The Experts.
Today we're talking about how to select the right abrasives for your grinding application, so let me show you what goes into this decision.
Grinding wheels are made up of two key components—the abrasive grains that handle the actual cutting and the bond that holds the grains together (and that supports them while they cut).
When it comes to grinding discs, flap wheels, and other abrasives used on power tools, you have four main options. Each type is unique and has its own distinctive properties for hardness, strength, fracture toughness, and impact resistance.
Your choices include…
- Aluminum oxide, the most common abrasive used in grinding wheels and the first grain that most offhand abrasives were introduced with.
- Typically used for grinding carbon steel, alloy steel, high speed steel, annealed malleable iron, wrought iron, and bronzes and similar metals, aluminum oxide is a good, entry-level grain for general purpose applications on steel.
- Up next we have Zirconia alumina, which is actually a family of abrasives made with a different percentage of aluminum oxide and zirconium oxide. These abrasives are tough, durable, and work well in rough grinding applications like cut-off operations. You can step up to a zirconium grit product for better life in steel applications, and for less heat buildup when working with stainless steel.
- The next option is silicon carbide, an abrasive used for grinding gray iron, chilled iron, brass, soft bronze, and aluminum. Other applications where silicon carbide works well include stone, rubber, and non-ferrous materials.
- Finally, ceramic aluminum oxide is exceptionally hard and strong and is used primarily for precision grinding. It works well with most materials due to its fracturing (or wearing) capability. In other words, ceramic tends to fracture with sharper edges than aluminum oxide or zirconia alumina. This allows you to cut faster and longer, and get more tool life out of ceramic products.
When grinding aluminum, high heat levels can make the material “stick” or build up on the abrasive tool. Using ceramic wheels can help alleviate this problem because ceramic lends itself to rapid material removal, thus reducing the chances of heat buildup.
When picking the right abrasive for your application, you’ll also want to consider the grit—those hard, abrasive grains that do the actual cutting or material removal.
For faster removal rates, look for a coarser grit such as 36 or 40.
And for a better finish, use a finer grade grit like 60, 80, or 120.
Thanks for watching this edition of Grainger Ask The Experts. For more helpful tips and videos, check out the full series.