Seek the conversion method between bolt preload and installation torque
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What is the method for converting bolt preload to installation torque?
Pre-tightening torque Mt = K × P0 × d × 0.001 N.m. Where K is the tightening coefficient; d is the nominal diameter of the thread in mm; P0 is the pre-tightening force in N. P0 = σ0 × As, and As can also be found using the formula below: As = π × ds × ds/4, where ds is the calculated diameter of the critical cross-section of the thread portion, ds = (d2 + d3)/2, and d3 = d1 – H/6. H represents the nominal working height of the thread teeth. σ0 = (0.5–0.7)σs, where σs is the yield limit of the bolt material in N/mm2 (it depends on the strength grade and the material used). The value of K can be found from tables (the formula for calculating K is not provided here). Bolt pre-tightening force – Baidu Baike: https://baike.baidu.com/item/%E8%9E%BA%E6%A0%93%E9%A2%84%E7%B4%A7%E5%8A%9B/9065484?fr=aladdin
Those who are not involved in installation don’t need to calculate this, right? The installation specifications should have relevant regulations on this