M12 Grade 4.6 Torque Specification

Torque Values by Surface Condition

Stress area: 84.27 mm² · Proof load: 18,961 N · Clamp load (75%): 14,221 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	34.1	25.2	301.8	347.7
Oiled	0.15	25.6	18.9	226.6	261.0
Zinc Plated	0.18	30.7	22.6	271.7	313.1
Waxed	0.1	17.1	12.6	151.3	174.4
MoS₂	0.12	20.5	15.1	181.4	209.0
Galvanized	0.25	42.7	31.5	377.9	435.4

Stress area: 92.07 mm² · Proof load: 20,716 N · Clamp load (75%): 15,537 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	37.3	27.5	330.1	380.4
Oiled	0.15	28.0	20.7	247.8	285.5
Zinc Plated	0.18	33.6	24.8	297.4	342.6
Waxed	0.1	18.6	13.7	164.6	189.7
MoS₂	0.12	22.4	16.5	198.3	228.4
Galvanized	0.25	46.6	34.4	412.4	475.2

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 225 MPa × 84.27 mm² = 14,221 N

Step 2 — Torque (dry): T = 0.20 × 0.0120 m × 14,221 N = 34.1 N·m

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

Non-critical assemblies, light-duty applications, general-purpose hardware where high strength is not required

• 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

Class4.6

Diameter12 mm

Pitch (coarse)1.75 mm

Tensile400 MPa

Yield240 MPa

Proof225 MPa