The bolt is used in porcelain insulator/ceramic insulator. The bolt for porcelain insulator/ceramic insulator is hot DIP galvanized. And the bolt thread is according to ANSI or metric.
--material of bolt for porcelain insulator/ceramic insulator: Forged-steel
-- hot DIP galvanization
--standard of bolt for porcelain insulator/ceramic insulator: ANSI or metric thread
-- bolt for porcelain insulator/ceramic insulator: Used in 15kv post insulaotor