Grinding wheels, also known as abrasive wheels, are used for many different tasks.
They can be used to strip paint and remove rust, for example. They can also polish imperfections from a finish or smooth a welded joint. They’re an essential tool found at many jobsites and choosing the right abrasive material is extremely important.
Today, Ram Products is going to help you choose the perfect abrasive tool for the task at hand. We’ll explain which abrasives are suited for which tasks and which backing and coverage systems you should use for different jobs.
Abrasive materials come in all different varieties. Some are suited for rugged work on rough surfaces, while others are designed for softer materials and hand-based work.
Aluminum oxide is a synthetic material derived from bauxite and is the most popular abrasive today. It’s prized for its toughness but can also be used on a diverse range of materials. Since it comes in a number of different grits – from ultrafine to rugged – aluminum oxide is suited for materials like:
Most people use aluminum oxide for wood sanding, where it comes in grit ratings between 120 and 220.
Ceramic is the industrial version of aluminum oxide. It is particularly suited for heavy metal removal and comes in medium, coarse, and extremely coarse grit ratings.
Emery is typically backed by cloth and comes in grit ratings of either medium or coarse. It’s a natural product that includes a small amount of iron oxide mixed with aluminum oxide. Emery is particularly suited for metal polishing due to its flexibility and its lower abrasion rating than ceramic.
Garnet is one of the softest abrasive materials and is typically found in medium and fine grit ratings. Its low abrasion makes it ideal for light wood sanding and gentle paint removal. Rougher grits are suited for smoothing metal. Since it is often backed by lightweight papers, garnet is ideal for small hand-sanding tasks.
Silicon Carbide combines synthetic and natural materials and is typically backed by waterproof paper. It is generally found in fine and ultra-fine abrasion ratings and is ideal for fine abrasive work with wood finishes, plastic, glass, nonferrous metal, and ceramic. Additionally, the waterproof paper backing allows water to be used as a cutting lubricant.
Zirconia Alumina is an industrial-grade abrasive made of a synthetic combination of zirconium oxide and aluminum oxide. It is available in medium, coarse, and extremely coarse grit ratings and is ideal for medium metal removal, weld smoothing, and other industrial tasks.
There are two main types of abrasive coverage systems, including closed-coat and open-coat. Belts, discs, and sheets are all typically available in closed-coat and open-coat options.
A closed-coat abrasive tool features a surface totally covered by abrasive material. This provides a fine finish and higher cutting power. However, the main downside of closed-coat abrasive tools is that they frequently clog with debris. They’re ideal for sanding hard materials, including oak and maple hardwoods and steel.
An open-coat abrasive tool has an abrasive surface on 50% to 70% of its total area. This makes it less prone to clogging, but leaves a coarser finish. Open-coat abrasive sheets, belts, and discs, are ideal for softer materials like resinous softwoods (white and yellow pine, for example) or primer and topcoat paints.
Abrasive sheets, discs, and belts are backed by either paper or cloth. However, there are many different weight ratings for cloth and paper.
Cloth is typically used on belts and discs. Cloth weight ratings include JF, J, XF, X YX, and YY. JF, J, XF, and X are lighter and more flexible than YX and YY.
Paper is typically used on sheets, although emery abrasives use cloth. Paper weight ratings include A, C, D, and E. A and C are lighter and more flexible than D and E.
Grinding machine horsepower
Your grinding machine requires different abrasives depending on its horsepower. A high horsepower grinding machine is best-suited to harder grades and smaller grain sizes, while a low horsepower machine is best-suited to softer grades and larger grain sizes.
Abrasive grain size
We’ve talked about grain materials above, but it’s important to recognize that each grain material is separated into different grain sizes. A larger grain size should be used on softer materials – like mild steel and green concrete – while a smaller grain size is suited for harder steels and curated concretes.
You can view our selection of grinding wheels here. Ram Products offers grinding wheels in packages of 1 to 50. All grinding wheels feature aluminum oxide grain, which is the most versatile abrasive available and is suited to a wide variety of materials and tasks, including wood, drywall, metal, metal welds, rust and paint removal, wood sanding, and more.