M7 Grade 4.6 Torque Specification

Torque Values by Surface Condition

Stress area: 28.86 mm² · Proof load: 6,494 N · Clamp load (75%): 4,870 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	6.8	5.0	60.2	69.3
Oiled	0.15	5.1	3.8	45.1	52.0
Zinc Plated	0.18	6.1	4.5	54.0	62.2
Waxed	0.1	3.4	2.5	30.1	34.7
MoS₂	0.12	4.1	3.0	36.3	41.8
Galvanized	0.25	8.5	6.3	75.2	86.7

Stress area: 31.23 mm² · Proof load: 7,027 N · Clamp load (75%): 5,270 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	7.4	5.5	65.5	75.5
Oiled	0.15	5.5	4.1	48.7	56.1
Zinc Plated	0.18	6.6	4.9	58.4	67.3
Waxed	0.1	3.7	2.7	32.7	37.7
MoS₂	0.12	4.4	3.2	38.9	44.9
Galvanized	0.25	9.2	6.8	81.4	93.8

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 225 MPa × 28.86 mm² = 4,870 N

Step 2 — Torque (dry): T = 0.20 × 0.0070 m × 4,870 N = 6.8 N·m

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

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.

SizeM7

Class4.6

Diameter7 mm

Pitch (coarse)1.0 mm

Tensile400 MPa

Yield240 MPa

Proof225 MPa