A Hex Bolt is a form of threaded fastener with an external male thread. And bolts are very closely related to screws.
These are grade 4.6 and 8.8. The first digit so relates to the ultimate strength of the material. Because the second is the ratio of yield stress to ultimate strength. Thus grade 4.6 bolts have an ultimate material strength of 400N/mm2. And the uield (or proof) stress is 60% of the ultimate strength.
Grade 8.8 Bolts are manufactured using medium carbon steel that has been quenched and tempered. Used in railroad equipment, motors, engines and processing equipment, grade 8.8 bolts exhibit good tensile strength and perform well in most environments.
Grade 10.9 metric bolts are manufactured. Using medium carbon steel, medium carbon steel alloy and low carbon boron steel that has been quenched and tempered. Used in automotive applications and for bolting large and forged parts, metric 10.9 bolts exhibit high tensile strength and good wear resistance.
Grade B – Intended for Heavy Hex Head, these bolts, studs/threaded rod having a tensile strength of 60 to 100 ksi and intended for flanged joins in piping systems with cast iron flanges.
Sizes Available M6 to M64
Length 25mm to 500mm
Hot Forged Bolts and Nuts
M72 to M125
Length 500 – 2 Mtr