M12 Grade 5.6 Torque Specification

Torque Values by Surface Condition

Stress area: 84.27 mm² · Proof load: 23,596 N · Clamp load (75%): 17,697 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	42.5	31.3	376.2	433.4
Oiled	0.15	31.9	23.5	282.3	325.3
Zinc Plated	0.18	38.2	28.2	338.1	389.5
Waxed	0.1	21.2	15.6	187.6	216.2
MoS₂	0.12	25.5	18.8	225.7	260.0
Galvanized	0.25	53.1	39.2	470.0	541.5

Stress area: 92.07 mm² · Proof load: 25,780 N · Clamp load (75%): 19,335 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	46.4	34.2	410.7	473.2
Oiled	0.15	34.8	25.7	308.0	354.9
Zinc Plated	0.18	41.8	30.8	370.0	426.2
Waxed	0.1	23.2	17.1	205.3	236.6
MoS₂	0.12	27.8	20.5	246.1	283.5
Galvanized	0.25	58.0	42.8	513.3	591.4

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 280 MPa × 84.27 mm² = 17,697 N

Step 2 — Torque (dry): T = 0.20 × 0.0120 m × 17,697 N = 42.5 N·m

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

Moderate-duty industrial applications, machinery guards, medium-strength connections

• 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.

SizeM12

Class5.6

Diameter12 mm

Pitch (coarse)1.75 mm

Tensile500 MPa

Yield300 MPa

Proof280 MPa