Diameter: M4~M36 Standard:GB 5782-86 DIN931,DIN933,DIN960,DIN961,DIN558 eqv ISO4014,ISO4017,ISO8765,ISO8676,ISO4018 Mechanical performance:4.8/ 8.8 / 10.9 / 12.9 Grade A&B Length, surface processing and so on can be designed according to your requirements.