Choosing The Right Grinding Wheel For The Job
I grew up in rural Missouri and can remember sanding wood in my required junior high shop class. It was always by hand and you had all these different grits to choose from. The smaller the number, the more abrasive it was and as a junior high student it was hard to keep it all straight. The same could be said of grinding wheels. Not only are there different grit sizes but there are also different abrasive grain types. So which wheel is best in which situation?
What types of grinding wheels do we use?
There are many different types of grinding wheels out there for all kinds of different purposes. At HTS Coatings we typically use three types of grinding wheels; aluminum oxide, silicon carbide and diamond. We get into some pretty tough materials and sometimes have to remove a lot of material. We also work with a variety of materials so knowing when to use each kind of grinding wheel makes a huge difference.
Aluminum Oxide Grinding WheelsAluminum oxide wheels are versatile and relatively inexpensive. They work on most metals with a hardness under a 50 Rockwell C. We use it for metals such as steels and stainless steels. Not only can it be used for cylindrical grinding, but we also have it set up for surface grinding and internal diameter (I.D.) grinding as well. While steel grinding covers many machine parts, other materials required different grinding solutions.
Silicon Oxide Grinding WheelsSilicon carbide wheels are good for harder alloys but also for materials on the soft side such as copper, fused alloy steels or cast iron. These are also great for “gummy coatings” that would normally, for lack of a better term, gum up the pores on other wheels and negatively affect the cutting performance. We sometimes prefer this wheel as well because it dresses itself, depending on your desired finish, leaving a good working surface without the need for polishing. The cutting speed of silicon carbide wheels varies greatly depending on what material you are grinding.
Diamond Grinding WheelsDiamond wheels are the toughest we use. We see a lot of hardened materials and use it to finish a lot of our tungsten carbide coatings. These wheels are great for hardened steels and other materials with hardnesses over 50 Rockwell C. These wheels can also remove a lot of material in a short amount of time. Like aluminum oxide, we use diamond grinding wheels for cylindrical, surface and I.D. grinding.
Material Type Determines Grinding Wheel TypeThere are many other types of grinding wheels out there, but these are three we find most useful in the types of grinding we do and the materials we work with. Some things to consider when choosing a type of grinding wheel are the hardness of the material you are working with, the amount of material you are trying to remove and the type of surface finish you require. To see all the ways we incorporate grinding at HTS Coatings, check out our Machining and Grinding page .