Mechanic tightening a bolt on a car engine using a ratchet wrench in a professional workshop setting

Metric Bolt Torque Chart

This article provides a reference chart for standard metric bolts, showing recommended maximum tightening torques for coarse-threaded bolts based on bolt diameter and property class. The values are derived from ISO 898, which defines the mechanical properties of fasteners made from carbon and alloy steel. See our torque conversion chart for In./Lbs. to Nm conversion.

Metric Bolt Torque Specs

Metric Bolt Torque Chart

Thread Size Grade 4.6 Grade 4.8 Grade 5.8 Grade 6.8 Grade 8.8 Grade 9.8 Grade 10.9 Grade 12.9
M3 0.8N⋅m 0.9N⋅m 1.2N⋅m 1.4N⋅m 1.6N⋅m 1.8N⋅m 2.3N⋅m 2.7N⋅m
M4 1.9N⋅m 2.2N⋅m 2.8N⋅m 3.3N⋅m 3.7N⋅m 4.2N⋅m 5.4N⋅m 6.3N⋅m
M5 3.7N⋅m 4.4N⋅m 5.6N⋅m 6.6N⋅m 7.0N⋅m 7.8N⋅m 10.0N⋅m 11.7N⋅m
M6 6.4N⋅m 7.5N⋅m 9.6N⋅m 11.2N⋅m 11.8N⋅m 13.3N⋅m 17.0N⋅m 19.9N⋅m
M8 15.4N⋅m 18.2N⋅m 23.3N⋅m 27.3N⋅m 28.8N⋅m 32.3N⋅m 41.3N⋅m 48.3N⋅m
M10 30.5N⋅m 36.0N⋅m 46.1N⋅m 54.0N⋅m 57.3N⋅m 64.1N⋅m 81.8N⋅m 95.7N⋅m
M12 53.2N⋅m 62.7N⋅m 80.3N⋅m 94.1N⋅m 99.8N⋅m 112N⋅m 143N⋅m 167N⋅m
M14 79.5N⋅m 93.8N⋅m 120N⋅m 141N⋅m 149N⋅m 167N⋅m 214N⋅m 250N⋅m
M16 123N⋅m 145N⋅m 186N⋅m 218N⋅m 248N⋅m 277N⋅m 354N⋅m 413N⋅m
M18 170N⋅m 200N⋅m 256N⋅m 300N⋅m 340N⋅m 380N⋅m 485N⋅m 567N⋅m
M20 250N⋅m 294N⋅m 377N⋅m 442N⋅m 500N⋅m –N⋅m 690N⋅m 809N⋅m
M22 335N⋅m 395N⋅m 507N⋅m 594N⋅m 672N⋅m 752N⋅m 960N⋅m 1123N⋅m
M24 430N⋅m 507N⋅m 650N⋅m 762N⋅m 865N⋅m –N⋅m 1195N⋅m 1395N⋅m
M27 625N⋅m 737N⋅m 945N⋅m 1108N⋅m 1257N⋅m 1406N⋅m 1796N⋅m 2100N⋅m
M30 855N⋅m 1009N⋅m 1294N⋅m 1517N⋅m 1719N⋅m –N⋅m 2377N⋅m 2774N⋅m
Important Notes: These are recommended maximum tightening torques for dry, unlubricated threads with standard pitch. Reduce torque by 10-15% for lubricated bolts. Values marked with “-” indicate grades not commonly available for that size. Always refer to manufacturer specifications when available. Grade numbers indicate tensile strength (first digits) and yield strength ratio (last digit). Use proper torque wrench calibration and tightening procedures.

Parting Thoughts

MISUMI USA offers a wide range of screws and bolts—both standard and metric—including hex head bolts, narrow head bolts, square head bolts, and more. If you’re unsure which bolt product best suits your application, our engineering team is here to help. For more technical insights, explore our other manufacturing-focused tables and articles, such as a machine screw size chart.

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Author: Scott Bredemann | Updated: 6/30/2025

Disclaimer:
The content on this webpage is for informational purposes only. MISUMI makes no guarantees, expressed or implied, regarding the accuracy, completeness, or validity of the information. Performance parameters, tolerances, designs, materials, or processes should not be assumed to reflect third-party suppliers’ or manufacturers’ deliverables within MISUMI’s network. Buyers are responsible for specifying their part requirements