M14 Grade 12.9 Torque Specification

Torque Values by Surface Condition

Stress area: 115.44 mm² · Proof load: 111,977 N · Clamp load (75%): 83,983 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	235.2	173.5	2081.7	2398.4
Oiled	0.15	176.4	130.1	1561.3	1798.8
Zinc Plated	0.18	211.6	156.1	1872.8	2157.7
Waxed	0.1	117.6	86.7	1040.8	1199.2
MoS₂	0.12	141.1	104.1	1248.8	1438.8
Galvanized	0.25	293.9	216.8	2601.2	2997.0

Stress area: 124.55 mm² · Proof load: 120,814 N · Clamp load (75%): 90,610 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	253.7	187.1	2245.4	2587.0
Oiled	0.15	190.3	140.4	1684.3	1940.5
Zinc Plated	0.18	228.3	168.4	2020.6	2328.0
Waxed	0.1	126.9	93.6	1123.2	1294.0
MoS₂	0.12	152.2	112.3	1347.1	1552.0
Galvanized	0.25	317.1	233.9	2806.6	3233.5

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 970 MPa × 115.44 mm² = 83,983 N

Step 2 — Torque (dry): T = 0.20 × 0.0140 m × 83,983 N = 235.2 N·m

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

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.

SizeM14

Class12.9

Diameter14 mm

Pitch (coarse)2.0 mm

Tensile1220 MPa

Yield1100 MPa

Proof970 MPa