M24 Grade 5.8 Torque Specification

Torque Values by Surface Condition

Stress area: 352.5 mm² · Proof load: 133,950 N · Clamp load (75%): 100,462 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	482.2	355.7	4267.8	4917.1
Oiled	0.15	361.7	266.8	3201.3	3688.3
Zinc Plated	0.18	434.0	320.1	3841.2	4425.6
Waxed	0.1	241.1	177.8	2133.9	2458.5
MoS₂	0.12	289.3	213.4	2560.5	2950.0
Galvanized	0.25	602.8	444.6	5335.2	6146.9

Stress area: 384.42 mm² · Proof load: 146,080 N · Clamp load (75%): 109,560 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	525.9	387.9	4654.6	5362.7
Oiled	0.15	394.4	290.9	3490.7	4021.8
Zinc Plated	0.18	473.3	349.1	4189.1	4826.3
Waxed	0.1	262.9	193.9	2326.9	2680.8
MoS₂	0.12	315.5	232.7	2792.4	3217.2
Galvanized	0.25	657.4	484.9	5818.5	6703.6

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 380 MPa × 352.5 mm² = 100,462 N

Step 2 — Torque (dry): T = 0.20 × 0.0240 m × 100,462 N = 482.2 N·m

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

General industrial fastening, equipment mounting, moderate structural loads

• 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.

SizeM24

Class5.8

Diameter24 mm

Pitch (coarse)3.0 mm

Tensile520 MPa

Yield420 MPa

Proof380 MPa