... Certification Ningbo Zhenhai Hualong Fasteners Co., Ltd. Manufacturer of bolts ,nuts,wcrews,washers and other fasteners.We often make the ... best you can trust. Looking forward to your cooperataionRegarding to Bolts StandardDIN931,DIN933,DIN6914,ASTM A325M,ASTMA325, ASTM A-10, ... steel and so onSizeM6-M42 LengthM16-300Type of headSquare,Hex,Flange,Hex socket,T-Head and other you can chooseSurface ...