In modern systems requiring high precision and safety, each bolt size has its own standard torque corresponding to: bolt diameter, material strength grade, lubrication or dry conditions, and working environment (temperature, vibration)
1. Stainless steel tightening torque (Nm)
Stainless steel bolts typically have a lower tightening torque than steel bolts of the same size due to their characteristics: high friction, susceptibility to thread jamming, and lower strength compared to high-strength steel.
Bolt Size Stainless steel tightening torque (Nm)
M6 6 – 8 Nm
M8 15 – 20 Nm
M10 30 – 40 Nm
M12 50 – 65 Nm
M16 120 – 150 Nm
2. Automotive bolt tightening torque chart (common)
In the automotive industry, torque is extremely tightly controlled because it is directly related to safety..
Location Standard tightening torque (Nm)
Wheel bolts 90 – 120 Nm
Cylinder head bolts 40 – 100 Nm
Wheel axle bolts 150 – 300 Nm
Suspension bolts 100 – 200 Nm
3. High-Strength Steel Bolt Torque ChartThis group is widely used in: steel structures, industrial machinery, and precision mechanics. Torque increases with strength grade.
Size8.8 (Nm)10.9 (Nm)12.9 (Nm)
M825 35 40
M1050 7085
M1285120145
M16200280330
M20400550650
4. Bolt tightening torque chart for electromechanical equipment Insufficient tightening torque: contact resistance increases, heat is generated → equipment burns out.
Size Tightening torque (Nm)
M55 – 6 Nm
M68 – 10 Nm
M818 – 22 Nm
M1035 – 45 Nm
The table above is for reference only. In practice, torque adjustment is necessary when: Lubrication present → reduce torque by ~10–20% High vibration environment → increase torque or use threadlocker High temperature → changes material properties See more: Torque error: The “hidden cost” you are unaware of
