Metric bolt grades and strength calculator was developed to show proof strength, tensile strength,
Vickers / Brinell hardness,
minimum breaking torque and stress area of metric bolts and screws made of carbon steel and alloy
steel. Mechanical properties of grade 4.6, 4.8, 5.6, 5.8, 6.8, 8.8, 9.8, 10.9 and 12.9 are covered and this calculator was developed according to ISO 898-1 "Mechanical properties of fasteners made of carbon steel and alloy steel - Part 1:
Bolts, screws and studs" and ISO 898-7 – Mechanical properties of fasteners -Part 7: Torsional test and minimum torques for bolts and screws with nominal diameters 1 mm to 10 mm standard.
Some important notes from ISO 898 metric screw threads standards:
- Standard specifies the mechanical properties of bolts, screws and studs made of carbon steel and alloy
steel when tested at an ambient temperature range of 10 °C to 35 °C. Fasteners conforming to the requirements of ISO 898 are used in applications ranging from −50 °C
to +150 °C.
- ISO 898 applies to bolts, screws and studs with coarse pitch thread M1.6 to M39 and fine pitch thread M8 X 1 to M39 X 3 with triangular ISO thread
- It does not apply to set screws and similar threaded fasteners
- The minimum breaking torques are not valid for hexagon socket set screws.