M5 Grade 10.9 Torque Specification

Torque Values by Surface Condition

Stress area: 14.18 mm² · Proof load: 11,769 N · Clamp load (75%): 8,827 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	8.8	6.5	77.9	89.7
Oiled	0.15	6.6	4.9	58.4	67.3
Zinc Plated	0.18	7.9	5.8	69.9	80.6
Waxed	0.1	4.4	3.2	38.9	44.9
MoS₂	0.12	5.3	3.9	46.9	54.0
Galvanized	0.25	11.0	8.1	97.4	112.2

Stress area: 16.13 mm² · Proof load: 13,388 N · Clamp load (75%): 10,041 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	10.0	7.4	88.5	102.0
Oiled	0.15	7.5	5.5	66.4	76.5
Zinc Plated	0.18	9.0	6.6	79.7	91.8
Waxed	0.1	5.0	3.7	44.3	51.0
MoS₂	0.12	6.0	4.4	53.1	61.2
Galvanized	0.25	12.6	9.3	111.5	128.5

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 830 MPa × 14.18 mm² = 8,827 N

Step 2 — Torque (dry): T = 0.20 × 0.0050 m × 8,827 N = 8.8 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.

SizeM5

Class10.9

Diameter5 mm

Pitch (coarse)0.8 mm

Tensile1040 MPa

Yield940 MPa

Proof830 MPa