Metric bolt torque calculator according to VDI 2230 standard for shank bolts with metric standard thread according to ISO 262; hexagonal bolts according to DIN EN ISO 4014 to 4018, hexalobular external driving head bolts according to DIN 34800 or cylindrical bolts according to DIN EN ISO 4762 and hole ”medium“ according to ISO 273 (DIN EN 20273).
Based on theory given in VDI standard, it's aimed to utilize the bolt strength to the greatest extent. Normally 90 % of minimum yield point (Rp0.2min) is allowed to be utilized. The default value for utilization factor is therefore set as 0.9 but can be changed.
Note: P - Pitch, d2- Pitch diameter of the bolt thread, d0- Diameter at the relevant smallest cross section, dh- hole diameter of clamped parts, s- Width across flats, μGmin-Coefficient of friction in the thread, μKmin-Coefficient of friction in the head bearing area, Rp0.2-0,2% proof stress of the bolt according to DIN EN ISO 898-1, DKm-Effective diameter for the friction moment at the bolt head or nut bearing area, A0-Appropriate minimum cross-sectional area of the bolt.