With a wide variety of grinding wheels on the market, choosing the right one for your application can be challenging. To make your selection a bit easier, we’ve broken down the characteristics that differentiate grinding wheels and what to consider when selecting one.

Grinding Wheel Differentiators

1. Abrasive Type

There are four main types of abrasive grains available for grinding discs. Each type has unique properties when it comes to hardness, strength, fracture toughness and resistance to impact. The choice of the abrasive is related to the material you are working on.

• • Aluminum Oxide
    Aluminum Oxide is the most common abrasive used in grinding wheels. It is used for everything from carbon to alloy steel, wrought iron, and bronze. This particular abrasive comes in a variety of styles that work with different materials. Be sure to look at the designation of the specific aluminum oxide abrasive and what it works best with.

• • Silicon Carbide
    Silicon Carbide works well on non-ferrous materials like rubber, stone, plastic, and glass, and also cuts through cast iron, soft bronze or aluminum. Expect to replace this abrasive more frequently than normal. It is very sharp, but can also be brittle, so it doesn’t last as long as an aluminum oxide surface.

• • Zirconia Alumina
    Zirconia Alumina uses a mix of aluminum oxide and zirconium oxide to create a durable surface that works great in cut-off applications for steel and steel alloys.

• Ceramic Aluminum Oxide
  Ceramic Aluminum Oxide is the most modern type of abrasive. This ceramic grain has a unique microcrystalline structure that is self-sharpening. This abrasive is exceptionally hard and strong. It is primarily used for precision grinding in demanding applications on steels and alloys that are the most difficult to grind.

2. Grit

Grit is related to the size of the abrasive grains distributed on the wheels. The higher the grit size, the finer the abrasive is. The basic descriptions of abrasive types range from coarse to medium to fine. Grinding wheels with a low grit size are commonly used in applications where the material finish is not important, and the focus is on material removal. On the other hand, fine grit wheels are preferred when finish is a fundamental aspect of the project.

3. Bond

Bond is the material that holds the abrasive grains together so they can cut effectively. The bond must wear away as the abrasive grains wear and are expelled so new sharp grains are exposed. Most grinding wheels are made with vitrified bonds, which consist of a mixture of carefully selected clays. These types of wheels are strong and porous and are not affected by water, acid, oils or variations in temperature. An important aspect to consider when it comes to bonds is their strength or grade.

Strong bonds, or hard grades, are recommended for soft materials, small or narrow areas of contact, or longer wheel life. Weak bonds, or soft grades, are preferable for hard materials, such as hard tool steels or carbides, for large areas of contact, or for rapid stock removal.

How to Choose the Right Wheel

The following questions can help you identify the right model for your application:

1. What material will you be grinding and how hard is it?
2. What needs to be removed from the material?
3. What type of machine will you be using?
4. What wheel speeds and feeds will be involved?
5. What is the size and hardness of the grinding contact area?
6. Will this be a wet or dry process?
7. What is the severity of the grinding required?
8. What is the dressing method?

In the end, selecting a grinding wheel is a process that requires a lot of time and thought, but if done right, can lead to great results.

Martin Industrial Supply works with top of the line grinding wheel suppliers like 3M, Norton, Weiler, and Milwaukee. Talk to a Martin Sales Rep or call 800.828.8116 and let us help you find the right abrasive  solution.