Finding the grinding wheel or cutting wheel you need depends on the materials you’ll be working with: metal, stone, concrete, etc.
Grinding wheels made of aluminum oxide are the most commonly used for working with metals. There are also abrasives made of zirconia alumina, a combination of aluminum oxide and zirconium-oxide.
Zirconia alumina is a heavy-duty substance that doesn’t splinter, so you don’t have to change the wheels as often. This abrasive may cost more than others, but it will last longer.
Aluminum oxide grinding discs can be used on ferrous metals, iron, steel, and nonferrous metals. Zirconia alumina will work on steel, iron, and bronze.
Pearl Abrasive Company offers a MAX-A-O, an aluminum oxide composite. It is said to grind cooler than the standard grinding wheel and fractures into smaller pieces, according to Troy Martin, sales associate at PaulB Hardware in Lititz, where they sell a wide selection of grinding discs and cutting wheels.
When grinding stainless steel, the grinding wheel has to be contaminant-free. Any contaminant will rust before you grind it, so you have to start with a new wheel, or grind only stainless steel using the wheel. Never mix wheel use when working with stainless steel, Martin cautions.
SRT (Synthetic Resinoid Technology, introduced by Pearl Abrasive Company) or wheels with a resin bond are especially suited for grinding stainless steel. Pearl’s SRT contains less than 0.1% of iron, sulfur, or chlorine elements in the abrasive material.
When working with nonferrous metals, silica carbide abrasives are best. These grinding wheels are made with anti-loading property to prevent the aluminum (a softer metal) from sticking.
A diamond cup wheel is best for professional masonry work. A wheel of silicon carbide grit can be used as an inexpensive alternative, although it may not be as efficient.
The most common sizes in grinding wheels are 4 1/2in to 7in, but PaulB does carry 4in, 6in, 9in, and 5in. Grinding wheels are commonly sold without hubs. If the washer and nut that came with your grinder is missing, you’ll need to buy a replacement or buy wheels that have the hub in them.
The thin, CGW Quickie Cut is a popular cutting wheel, according to Kenton Bucher, a PaulB LLC buyer specializing in grinding and cutting wheels. This type cuts aggressively and quickly, and comes as Type 1 (flat) and Type 27 (recessed). Use the Type 27 for flush cuts, when a recessed nut is needed.
Kenton says the industry is moving toward 3-in-1 wheels, which cut, grind and finish all in one.
Flap discs are used for grinding and come in sizes 4 ½in to 7in. The higher the grinder amp, the thicker the wheel choice.
The ceramic flap discs tend to last longer, Kenton says, and they’re more aggressive. There are new trimmable options that allow you to grind the discs back to the plastic to open up a fresh new set of paper.
For stripping paint and rust, use a porous wheel. For other uses, choose a wire wheel (which come flat, knotted, cupped, or crimped).
Wheels are labeled not only by abrasive type, but also by grit size, and grade of the grind.
Grit sizes range from 16 to over 100: The lower the number, the more coarse the grit. For surface prep, you’ll want to choose between super-fine, fine and medium grits. Choose a super-fine grit for finishing welding projects.
The grade of your wheel is labeled by letters, A-Z. Your hardest grade is at the end of the alphabet.
Keep in mind that there is no standard set across grinding wheel manufacturers. Each uses its own identifying method.
The PaulB Wholesale staff would be happy to help you discern which wheel is best for your project. Become a PaulB Wholesale customer!