... .coating: bright,Tin,TiCN, ALSIN-A,Oxide 1. Type:thread screw maker, roll forming tap, spiral fluted tap, spiral pointed tap2 ... . (Substandard size per customer's requirement are acceptable. )3. Type: Plug, Bottoming and Modified bottoming style.4. Thread Type: Long and ... representative for most suitable coating for your working material. thread screw maker