Protective Coatings for Fasteners
This SAE Information Report is provided as an advisory guide. Careful discretion as to application is recommended. The content has been presented as accurately as possible, but responsiblity for its application lies with the user. It covers finishes applied to fasteners and related topics, corrosion resistance, lubricity, electrical grounding, ultraviolet light, and embrittlement. Table 1 lists these coatings and their properties so that finish selection can be reasonably made in accordance with known and anticipated fastener assembly applications. Application of protective coatings will affect fastener dimensions. This is especially critical for the thread fit of mating parts because the pitch diameter increases by four times the coating thickness. Explanation is covered in Section 5.