1.standerd: DIN 6921 ,DINaa 933,DIN 6921 934aa etc. 2.material: titanium/zirconium/Tantalum/niobium/nickel. 3.M3*5~M32*400 1.standerd: DIN 6921 ,DIN 933,DIN 6921 934 etc.2.material: titanium and titanium alloy, zirconium and zirconium alloy, Tantalum and tantalum alloy, Niobium and niobium alloy, nickel and nickel alloy.3.specification: M3*5~~M32*400.