TABLE OF CONTENTS Commercial products and equipment in all classifications require finishes of one type or other. These finishes range from basic oxide coatings to the various paints and plastics to electrodeposited metals such as copper, chromium, nickel, etc.
The finish or plating used on any particular part should contribute to the engineering qualities of the final product and not merely to its cosmetic appeal. The desired finish could include weather protection, resistance to corrosive chemicals, heat resistance, electrical conductivity, wear resistance, and improved lubrication qualities.
It is the design engineer's responsibility to specify the finish characteristics and specifications on a part or assembly. Designers should be aware of the types of finishes and plating processes that are available commercially and how to specify them on the design and detail part drawings. Arbitrary selection of a finish or plating and its thickness range can lead to many design problems relating to corrosion, cost, and dimensional interference.
This chapter will familiarize the designer, engineer, and other personnel in the metalworking industries with the common finishing processes, procedures for specifying thicknesses of platings, and the appropriate industrial standard specifications that control these finishes.
The finishing processes and methods in common use for engineering applications are as follows:
Sanding or grinding
Brushing (scratch and satin)
Sandblasting
Shot peening and tumbling (metal or ceramic ball)
Burnishing
Mechanical powder plating
Polishing
Etching
Bonderite
Alodine
Iridite
Phosphatizing
Passivating (stainless steels)
Black oxide
Blueing
Teflon coating
Other plastic coatings
Sulfuric acid...
