... 1. Head Type: hex head, T head, Square Round/head 2. Finish: ZP/YZP, HDG, Plain, etc. Non-standard BoltsIt ... 's also called customized bolts.Material: carbon steel, stainless steel,BrassGrade: ... .8,8.8,10.9,12.9; SAE J429 Gr. 2,5,8Finish: Plain, ZP, Black and hot-dip galvanized, etc ...