M30 Grade 4.6 Torque Specification

Torque Values by Surface Condition

Stress area: 560.59 mm² · Proof load: 126,133 N · Clamp load (75%): 94,600 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	567.6	418.6	5023.7	5787.9
Oiled	0.15	425.7	314.0	3767.8	4340.9
Zinc Plated	0.18	510.8	376.7	4521.0	5208.7
Waxed	0.1	283.8	209.3	2511.8	2894.0
MoS₂	0.12	340.6	251.2	3014.6	3473.2
Galvanized	0.25	709.5	523.3	6279.6	7234.9

Stress area: 621.2 mm² · Proof load: 139,770 N · Clamp load (75%): 104,828 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	629.0	463.9	5567.1	6414.0
Oiled	0.15	471.7	347.9	4174.9	4810.0
Zinc Plated	0.18	566.1	417.5	5010.4	5772.6
Waxed	0.1	314.5	232.0	2783.6	3207.0
MoS₂	0.12	377.4	278.4	3340.3	3848.4
Galvanized	0.25	786.2	579.9	6958.5	8017.0

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 225 MPa × 560.59 mm² = 94,600 N

Step 2 — Torque (dry): T = 0.20 × 0.0300 m × 94,600 N = 567.6 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.

SizeM30

Class4.6

Diameter30 mm

Pitch (coarse)3.5 mm

Tensile400 MPa

Yield240 MPa

Proof225 MPa