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.