Understanding proper grinding wheel selection makes it easy for you to do the job faster and more effectively.
The grinding wheel is an abrasive cutting tool responsible for the removal of excess unnecessary parts of the workpiece and for optimizing surface finishing. There are a lot of factors to consider in selecting which wheels are to be used in a particular operation:
Materials to be ground
The first thing to consider here is the material to be ground, for that will determine which abrasives you will want to use. The hardness and softness of the material can greatly affect the function of the grinding wheel, so proper matching is highly recommended.
Grinding steels and alloys, for example, should require aluminum oxide abrasives.
Generally, hard metals can resist the penetration of the wheel grains which can cause them to get dull quickly. These metals should require wheels that have the right combination of fine grit size and softer grade to expose fresh, sharp cutting points. On the other hand, soft and ductile metals that are easily penetrated should use hard-grade wheels with coarse grit.
Amount of stock
Another point of consideration is the amount of stock subject to removal. Coarser grits are more capable of rapidly removing stock since they can better penetrate and make heavier cuts.
For materials that are harder to penetrate, the use of finer grits will make quick work, as they have more cutting points to cut away the unnecessary parts.
The wheel speed determines what type of wheel bond to use in an abrasive machining process. There are organic types of bonds for conventional grinding wheels which are used for smooth grinding, while vitrified bonds work best in fast cutting processes. However, these vitrified bonds may break at high speed and pressure. The strength of these bonds is typically designated in the grade of the wheel.
Area of grinding contact
The contact between the wheels and the workpiece is highly crucial to the outside diametrical surface of the material. For different areas, there are also different types of grades you can use to optimize the part-cutting process. Broad areas of contact indicate the use of wheels with coarser grits and soft grades. This helps to maintain a cool cutting action even under heavier loads that can be incurred by the size of the workpiece.
The severity of grinding action
Severe conditions during the grinding course may affect the outcome of the ground workpiece. Some abrasives are intently designed for high-pressure environments. Make sure to pick the right wheels that fit their designated machining temperature.
Grinding machine horsepower
The machine horsepower will determine what grade will be applied to the operation. Generally, wheels with higher grades should be used on machines that have the higher horsepower. If the horsepower is greater than the wheel diameter, choose a wheel with a harder grade. If it’s less than the wheel diameter, a wheel with a softer grade should be used.