M6 Grade 5.6 Torque Specification

Torque Values by Surface Condition

Stress area: 20.12 mm² · Proof load: 5,634 N · Clamp load (75%): 4,225 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	5.1	3.8	45.1	52.0
Oiled	0.15	3.8	2.8	33.6	38.7
Zinc Plated	0.18	4.6	3.4	40.7	46.9
Waxed	0.1	2.5	1.8	22.1	25.5
MoS₂	0.12	3.0	2.2	26.6	30.6
Galvanized	0.25	6.3	4.6	55.8	64.2

Stress area: 22.03 mm² · Proof load: 6,168 N · Clamp load (75%): 4,626 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	5.6	4.1	49.6	57.1
Oiled	0.15	4.2	3.1	37.2	42.8
Zinc Plated	0.18	5.0	3.7	44.3	51.0
Waxed	0.1	2.8	2.1	24.8	28.6
MoS₂	0.12	3.3	2.4	29.2	33.7
Galvanized	0.25	6.9	5.1	61.1	70.4

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 280 MPa × 20.12 mm² = 4,225 N

Step 2 — Torque (dry): T = 0.20 × 0.0060 m × 4,225 N = 5.1 N·m

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

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.

SizeM6

Class5.6

Diameter6 mm

Pitch (coarse)1.0 mm

Tensile500 MPa

Yield300 MPa

Proof280 MPa