The description is different,so the mechanical property differ much. Usually high-strength bolts's proof load is bigger than the specifications of ordinarye.
Ordinary bolt material is Q235 (A3).High strength bolts material is 45 # steel, alloy steel (such as 20MnTiB, 35VB) or the other high-quality materials, which has heat treatment, then increased strength.
The difference between the two is the strength of different materials.
The first point: from the raw materials:
High strength bolts are made of high strength materials. High-strength bolts and assembly screw, nuts and washers all are high strength steel.Normally are 45 steel, 40 boron steel, 20 manganese titanium boron steel. Ordinary bolt normally is Q235 steel.
The second point: from the strength level point:
High strength bolts is up than Grade8.8. Normal bolt strength level is lower, generally 4.4, 4.8, 5.6. (8.8S and 10.9S for the structure steel bolt)
