M27 Grade 4.6 Torque Specification

Torque Values by Surface Condition

Stress area: 459.41 mm² · Proof load: 103,367 N · Clamp load (75%): 77,525 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	418.6	308.7	3704.9	4268.5
Oiled	0.15	314.0	231.6	2779.1	3201.9
Zinc Plated	0.18	376.8	277.9	3335.0	3842.3
Waxed	0.1	209.3	154.4	1852.5	2134.3
MoS₂	0.12	251.2	185.3	2223.3	2561.5
Galvanized	0.25	523.3	386.0	4631.6	5336.2

Stress area: 496.18 mm² · Proof load: 111,640 N · Clamp load (75%): 83,730 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	452.1	333.5	4001.4	4610.2
Oiled	0.15	339.1	250.1	3001.3	3457.9
Zinc Plated	0.18	406.9	300.1	3601.4	4149.2
Waxed	0.1	226.1	166.8	2001.2	2305.6
MoS₂	0.12	271.3	200.1	2401.2	2766.5
Galvanized	0.25	565.2	416.9	5002.4	5763.5

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 225 MPa × 459.41 mm² = 77,525 N

Step 2 — Torque (dry): T = 0.20 × 0.0270 m × 77,525 N = 418.6 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.

SizeM27

Class4.6

Diameter27 mm

Pitch (coarse)3.0 mm

Tensile400 MPa

Yield240 MPa

Proof225 MPa