Polishing

Polishing

Polishing - Polishing is generally done after grinding with a solid abrasive wheel and is followed by buffing. Polishing differs from grinding, in that; an almost negligible amount of stock is actually removed. Polishing is done by (the cutting action of millions of small abrasive grains adhering to) an endless belt or flexible wheel.

The purpose of polishing is to remove

(i) Scratches

(ii) Tool marks and

(iii) Other similar irregularities (defects) produced on the work surface from previous machining operations and;

(iv) Thus to improve the surface finish. Dimensional accuracy is not to be closely controlled.

Metals are polished to improve their appearance and as a protection against oxidation.

The complete polishing sequence usually involves several steps, first to remove the initial scratches and defects from the work and then to gradually impart the final surface condition. The general practice is to polish the work with a succession of wheels set up with different grain sizes. The progression is from a coarse abrasive grit to a fine grit.