M16 Grade 10.9 Torque Specification

Torque Values by Surface Condition

Stress area: 156.67 mm² · Proof load: 130,036 N · Clamp load (75%): 97,527 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	312.1	230.2	2762.3	3182.5
Oiled	0.15	234.1	172.7	2072.0	2387.2
Zinc Plated	0.18	280.9	207.2	2486.2	2864.4
Waxed	0.1	156.0	115.1	1380.7	1590.8
MoS₂	0.12	187.3	138.1	1657.7	1909.9
Galvanized	0.25	390.1	287.7	3452.7	3977.9

Stress area: 167.25 mm² · Proof load: 138,818 N · Clamp load (75%): 104,113 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	333.2	245.8	2949.1	3397.7
Oiled	0.15	249.9	184.3	2211.8	2548.3
Zinc Plated	0.18	299.8	221.1	2653.5	3057.1
Waxed	0.1	166.6	122.9	1474.5	1698.9
MoS₂	0.12	199.9	147.4	1769.3	2038.4
Galvanized	0.25	416.5	307.2	3686.3	4247.1

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 830 MPa × 156.67 mm² = 97,527 N

Step 2 — Torque (dry): T = 0.20 × 0.0160 m × 97,527 N = 312.1 N·m

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

Structural steel (equivalent to ASTM A490), heavy machinery, high-strength critical joints, pressure vessels

• 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.

SizeM16

Class10.9

Diameter16 mm

Pitch (coarse)2.0 mm

Tensile1040 MPa

Yield940 MPa

Proof830 MPa