M22 Grade 4.6 Torque Specification

Torque Values by Surface Condition

Stress area: 303.4 mm² · Proof load: 68,265 N · Clamp load (75%): 51,199 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	225.3	166.2	1994.1	2297.4
Oiled	0.15	169.0	124.6	1495.8	1723.3
Zinc Plated	0.18	202.7	149.5	1794.0	2067.0
Waxed	0.1	112.6	83.0	996.6	1148.2
MoS₂	0.12	135.2	99.7	1196.6	1378.7
Galvanized	0.25	281.6	207.7	2492.4	2871.5

Stress area: 333.01 mm² · Proof load: 74,927 N · Clamp load (75%): 56,195 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	247.3	182.4	2188.8	2521.8
Oiled	0.15	185.4	136.7	1640.9	1890.6
Zinc Plated	0.18	222.5	164.1	1969.3	2268.9
Waxed	0.1	123.6	91.2	1094.0	1260.4
MoS₂	0.12	148.4	109.5	1313.5	1513.3
Galvanized	0.25	309.1	228.0	2735.8	3152.0

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 225 MPa × 303.4 mm² = 51,199 N

Step 2 — Torque (dry): T = 0.20 × 0.0220 m × 51,199 N = 225.3 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.

SizeM22

Class4.6

Diameter22 mm

Pitch (coarse)2.5 mm

Tensile400 MPa

Yield240 MPa

Proof225 MPa