They are the tool for the stage between grinding and polishing, and for jobs where dimensional change is not acceptable.
Non-woven material is a nylon web with abrasive grain bonded throughout, so it cuts continuously as it wears rather than loading up like coated abrasive. The grade (very fine, fine, medium, coarse) sets the cut rate and the finish. Coarse grades remove light scratches and blend welds; very fine grades produce a near-polished finish and are used before buffing.
Form follows the tool and the surface. Discs for angle grinders and die grinders, belts for file-type tools and belt sanders, wheels for bench and pedestal machines, hand pads for manual work in corners, and cross buffs for inside diameters.
Surface conditioning is also used for decorative finishing on stainless — a grain or satin finish is produced by running a non-woven belt or drum in one direction. Consistency of direction and pressure matters more than the grade for a uniform appearance.
