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 – 50 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 |
Wheel bolts | 40 – 100 Nm |
Wheel 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.
Size | 8.8 (Nm) | 10.9 (Nm) | 12.9 (Nm) |
M8 | 25 | 35 | 40 |
M10 | 50 | 70 | 85 |
M12 | 85 | 120 | 145 |
M16 | 200 | 280 | 330 |
M20 | 400 | 550 | 650 |
4. Bolt tightening torque chart for electromechanical equipment Insufficient tightening torque: contact resistance increases, heat is generated → equipment burns out.
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The able 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
