M5 Grade 12.9 Torque Specification

Torque Values by Surface Condition

Stress area: 14.18 mm² · Proof load: 13,755 N · Clamp load (75%): 10,316 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	10.3	7.6	91.2	105.0
Oiled	0.15	7.7	5.7	68.2	78.5
Zinc Plated	0.18	9.3	6.9	82.3	94.8
Waxed	0.1	5.2	3.8	46.0	53.0
MoS₂	0.12	6.2	4.6	54.9	63.2
Galvanized	0.25	12.9	9.5	114.2	131.5

Stress area: 16.13 mm² · Proof load: 15,646 N · Clamp load (75%): 11,735 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	11.7	8.6	103.6	119.3
Oiled	0.15	8.8	6.5	77.9	89.7
Zinc Plated	0.18	10.6	7.8	93.8	108.1
Waxed	0.1	5.9	4.4	52.2	60.2
MoS₂	0.12	7.0	5.2	62.0	71.4
Galvanized	0.25	14.7	10.8	130.1	149.9

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 970 MPa × 14.18 mm² = 10,316 N

Step 2 — Torque (dry): T = 0.20 × 0.0050 m × 10,316 N = 10.3 N·m

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

Socket head cap screws, racing/motorsport, aerospace, maximum strength applications — highest standard grade

• 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.

SizeM5

Class12.9

Diameter5 mm

Pitch (coarse)0.8 mm

Tensile1220 MPa

Yield1100 MPa

Proof970 MPa