National Standard for Double-Head Screws

The double-head bolts are manufactured in accordance with gb897-901 standards, the use of materials are: Q235, 45, 40Cr, 35CrMoA, Q345D, specifications are: M3mm-M100mm, the length can be customized according to the user's needs.

Double-head bolt standard: GB/T900-1988

National standard reference for double-headed bolts

GB2-end of outer screw-woven part of fastener

GB196-Normal thread base size

GB197-Normal Thread Tolerance and Fit

GB1167-transition inglion thread (spin into cast iron, steel body)

GB1180-overcurrent with thread (spin into aluminum crucible)

GB3098.1-Fastener mechanical performance Stainless steel bolts, screws, studs and nuts

GB3098.6-Fastener mechanical performance Stainless steel bolts, screws, studs and nuts

GB3103.1-Fastener toleranceBolts, screws and nuts

GB5267-threaded fasteners plating

GB5779.1 - Fastener surface defectbolts, screws and studs generally required

GB5779.3 - Special requirements for fastener surface defectbolts, screws and studs

GB90-fastener acceptance inspection, logo and packaging

GB1237- Marking method for fasteners