1.Standard: IFI-136;DIN975;DIN938;DIN938;DIN939;DIN940;DIN949;

   ASTMA193 B7;ASTM194 B7M;GB/T 897/898/899/900/901;

2.Size: can do it as your requested

3.material:carbon steel,stainless steel;alloy steel

4.Surface: self colour;black;z/p;H.D.G;Dacromet

5.grade:4.8s;8.8s;10.9s;12.9s