The material of the grinding disc should be softer than the workpiece material, so that the grinding powder particles can be embedded on the surface of the grinding disc. The grinding disc is made of pig iron, soft copper, purple copper, brass, lead, and hardwood. Lead and hardwood are only used for polishing after grinding the workpiece to the final size.
The hardest abrasive is diamond powder; Grinding hardened hardware with diamond powder. However, diamond powder is very expensive, so it is rarely used. The second hardest is diamond sand. Next are corundum powder, silicon carbide, and iron oxide powder. The most commonly used is diamond sand.
Using different grinding discs requires the use of different types of lubricants. The pig iron grinding plate needs to be lubricated with kerosene or gasoline. Soft steel grinding disc - using engine oil. Copper grinding disc - using engine oil, alcohol, and carbonated water. When the quality requirements for copper surfaces are particularly high, talc powder diluted with alcohol or iron lead powder mixed with Vaseline are used as lubricants. When grinding aluminum, use diatomaceous earth diluted with toluene and stearic acid or diatomaceous earth diluted with wood oil as a lubricant. When grinding copper alloys, use engine oil and fat as lubricants, mix the selected lubricant and grinding powder, and then carefully wipe the mixture.
