What is the difference between grinding and polishing?

1. Different processing methods for grinding and polishing

Grinding refers to the finishing of the machined surface through the relative movement of the grinding tool and the workpiece under certain pressure by using the abrasive particles coated or pressed on the grinding tool.

Polishing refers to the use of mechanical, chemical or electrochemical action to reduce the surface roughness of the workpiece to obtain a bright and smooth surface. It is the modification of the surface of the workpiece by using polishing tools and abrasive particles or other polishing media.

2. The processing precision of grinding and polishing is different

Grinding can be used to process various metal and non-metal materials, and the processed surface shapes include plane, inner and outer cylindrical and conical surfaces, convex and concave spherical surfaces, threads, tooth surfaces and other profiles. The machining accuracy can reach IT5～01, and the surface roughness can reach Ra0.63～0.01 micron.

Polishing does not improve the dimensional accuracy or geometric accuracy of the workpiece, but aims to obtain a smooth surface or specular gloss, and sometimes it is also used to eliminate gloss (matting). Usually a polishing wheel is used as a polishing tool. The polishing wheel is generally made of multiple layers of canvas, felt or leather, and the two sides are clamped by metal discs.