M10 Grade 10.9 Torque Specification

Torque Values by Surface Condition

Stress area: 58.0 mm² · Proof load: 48,140 N · Clamp load (75%): 36,105 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	72.2	53.3	639.0	736.2
Oiled	0.15	54.2	40.0	479.7	552.7
Zinc Plated	0.18	65.0	47.9	575.3	662.8
Waxed	0.1	36.1	26.6	319.5	368.1
MoS₂	0.12	43.3	31.9	383.2	441.5
Galvanized	0.25	90.3	66.6	799.2	920.8

Stress area: 61.2 mm² · Proof load: 50,796 N · Clamp load (75%): 38,097 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	76.2	56.2	674.4	777.0
Oiled	0.15	57.1	42.1	505.4	582.3
Zinc Plated	0.18	68.6	50.6	607.2	699.5
Waxed	0.1	38.1	28.1	337.2	388.5
MoS₂	0.12	45.7	33.7	404.5	466.0
Galvanized	0.25	95.2	70.2	842.6	970.8

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 830 MPa × 58.0 mm² = 36,105 N

Step 2 — Torque (dry): T = 0.20 × 0.0100 m × 36,105 N = 72.2 N·m

Proof stress per ISO 898-1:2013 Table 4. Stress area per ISO 898-1 Annex A. K-factor per VDI 2230.

Structural steel (equivalent to ASTM A490), heavy machinery, high-strength critical joints, pressure vessels

• Torque values are for standard hex bolts with ISO metric threads. Socket head cap screws may have different requirements.
• Lubrication reduces required torque significantly — using dry torque values on lubricated bolts risks exceeding yield strength.
• For critical or safety-related applications, always consult the manufacturer's specifications or applicable design standard (e.g., VDI 2230).
• Re-used bolts may have altered friction characteristics. Inspect threads before reuse.

SizeM10

Class10.9

Diameter10 mm

Pitch (coarse)1.5 mm

Tensile1040 MPa

Yield940 MPa

Proof830 MPa