TABLE OF CONTENTS Commercial products and equipment of all types and classifications require finishes of one type or other. These finishes range from basic oxide coatings to the various paints and plastics to electrodeposited and hot-dipped metals. The common electroplating metals include zinc, copper, chromium, nickel, silver, gold, palladium, rhodium, tin, lead, and cadmium. The hotdip metals include tin, lead, zinc, and aluminum.
The finish or plating used on any particular part should contribute to the engineering qualities of the finished product, and also to the cosmetic appearance, when required. The desired effects of the finish could include weather protection, resistance to corrosive chemicals, heat resistance, physical appearance, electrical conductivity, wear resistance, resistance to galvanic corrosion, 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 commercially available and how to specify them on the design and detail part drawings or specifications. Arbitrary selection of a finish or metallic plating and its thickness range can lead to many design problems relating to corrosion, dimensional interferences, and cost.
This chapter of the handbook is intended to familiarize the electromechanical design engineer, and other engineering support personnel, with common finishing processes, procedures for specifying thicknesses of plating, and the appropriate industrial standard specifications which control these finishes.
The finishing processes and methods in common use for engineering applications are outlined here.
Mechanical finishes
Sanding or grinding
