M24 Grade 4.6 Torque Specification

Torque Values by Surface Condition

Stress area: 352.5 mm² · Proof load: 79,312 N · Clamp load (75%): 59,484 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	285.5	210.6	2526.9	2911.3
Oiled	0.15	214.1	157.9	1894.9	2183.2
Zinc Plated	0.18	257.0	189.6	2274.6	2620.7
Waxed	0.1	142.8	105.3	1263.9	1456.2
MoS₂	0.12	171.3	126.3	1516.1	1746.8
Galvanized	0.25	356.9	263.2	3158.8	3639.4

Stress area: 384.42 mm² · Proof load: 86,494 N · Clamp load (75%): 64,871 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	311.4	229.7	2756.1	3175.4
Oiled	0.15	233.5	172.2	2066.7	2381.0
Zinc Plated	0.18	280.2	206.7	2480.0	2857.3
Waxed	0.1	155.7	114.8	1378.1	1587.7
MoS₂	0.12	186.8	137.8	1653.3	1904.8
Galvanized	0.25	389.2	287.1	3444.7	3968.8

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 225 MPa × 352.5 mm² = 59,484 N

Step 2 — Torque (dry): T = 0.20 × 0.0240 m × 59,484 N = 285.5 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.

SizeM24

Class4.6

Diameter24 mm

Pitch (coarse)3.0 mm

Tensile400 MPa

Yield240 MPa

Proof225 MPa