m12 bolt is a screw whose major diameter ( nominal diameter) is 12mm. the M means metric thread, often used with m12 hexagon nuts.
Features and Purpose of bolt m12
Hexagon bolt is the most widely used type of bolt. Its grade A and grade B bolts are used in important occasions with high assembly accuracy and bearing large impact, vibration or alternating load. The screw thread on the bolt is generally common thread, and the common thread bolt in West Asia has good self-locking property, which is mainly used in thin-walled parts or occasions under impact, vibration or alternating load. General bolts are made into part of the screw thread, full thread bolt is mainly used for the short nominal length of the bolt and the situation requiring a longer thread
Hexagon flange bolts
The head of hexagon flange bolt is composed of hexagon head and flange face. Its “ratio of support area to stress area” is larger than that of ordinary hexagon head bolt. Therefore, the bolt can bear higher preload and has better anti loosing performance. Therefore, it is widely used in automobile engine, heavy machinery and other products
Difference between ordinary bolt and high strength bolt
Normal bolts can be reused, but high tensile bolts can not be reused.
High tensile bolts are usually made of high-strength steel (45 steel (8.8s), which are prestressed bolts with friction type torsion
The required prestress is applied to the torque wrench, and the pressure bearing type is used to screw off the plum head. Ordinary bolts are generally made of ordinary steel (Q235) and need only be tightened.
Ordinary bolts are generally grade 4.4, grade 4.8, grade 5.6 and grade 8.8. High strength bolts are generally grade 8.8 and grade 10.9, of which grade 10.9 is the majority.
The screw hole of ordinary bolt is not necessarily larger than that of high strength bolt. In fact, the holes of ordinary bolts are relatively small.
The hole of Grade A and B of ordinary bolt is only 0.3 ~ 0.5mm larger than that of bolt. Grade C screw hole is generally 1.0 ~ 1.5mm larger than bolt.