No. 4 Finish is characterized by short, parallel polishing lines, which extend uniformly along the length of the coil. It is obtained by mechanically polishing a No. 3 finish with gradually finer abrasives. Depending on the requirements of the application, the final finish can be anywhere between 120 and 320 grit. Higher grit numbers produce finer polishing lines and more reflective finishes. The surface roughness is typically Ra 25 micro-inches or less. This general-purpose finish is widely used for restaurant and kitchen equipment, storefronts and food processing and dairy equipment. If a fabricator needs to blend in welds or do other refinishing, the resulting polishing lines are usually longer than on product polished by a producer or toll-polishing house.
Appliances, Architectural wall panels, Beverage equipment, Boat fittings, Bus shelters, Clean rooms, Column covers, Dairy equipment, Elevator doors and interiors, Escalator trim, Food processing equipment, Furniture Highway tank trailers, Hospital surfaces and equipment, Instrument or control panels, Kitchen equipment, Luggage handling equipment, Mass transit equipment, Restaurant equipment, Sinks, Sterilizers, Storefronts, Water fountains