SQUARE HEAD BOLT Material:Carbon steel. Diameter:5mm-50mm,1/4"-2" Length:8mm-300mm,5/16"-12" SQUARE HEAD BOLTS Material:Carbon steel.Diameter:5mm-50mm,1/4"-2"Length:8mm-300mm,5/16"-12"Thread:machine,wood.Grade:4.8,5.8,6.8,8.8,10.9 ASTM A325Finish:Plain,Zinc,Blank,Nickel,Chrome,H.D.GPacking:Carton,Small Box,Bag,Pallet