M45 Grade 4.6 Torque Specification

Torque Values by Surface Condition

Stress area: 1306.09 mm² · Proof load: 293,870 N · Clamp load (75%): 220,403 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	1983.6	1463.0	17556.3	20227.2
Oiled	0.15	1487.7	1097.3	13167.3	15170.4
Zinc Plated	0.18	1785.3	1316.8	15801.2	18205.1
Waxed	0.1	991.8	731.5	8778.2	10113.6
MoS₂	0.12	1190.2	877.8	10534.2	12136.7
Galvanized	0.25	2479.5	1828.8	21945.4	25284.0

Stress area: 1397.15 mm² · Proof load: 314,359 N · Clamp load (75%): 235,769 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	2121.9	1565.0	18780.4	21637.4
Oiled	0.15	1591.4	1173.8	14085.1	16227.8
Zinc Plated	0.18	1909.7	1408.5	16902.3	19473.6
Waxed	0.1	1061.0	782.6	9390.6	10819.2
MoS₂	0.12	1273.2	939.1	11268.8	12983.1
Galvanized	0.25	2652.4	1956.3	23475.7	27047.1

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 225 MPa × 1306.09 mm² = 220,403 N

Step 2 — Torque (dry): T = 0.20 × 0.0450 m × 220,403 N = 1983.6 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.

SizeM45

Class4.6

Diameter45 mm

Pitch (coarse)4.5 mm

Tensile400 MPa

Yield240 MPa

Proof225 MPa