M16 Grade 5.6 Torque Specification

Torque Values by Surface Condition

Stress area: 156.67 mm² · Proof load: 43,868 N · Clamp load (75%): 32,901 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	105.3	77.7	932.0	1073.8
Oiled	0.15	79.0	58.3	699.2	805.6
Zinc Plated	0.18	94.8	69.9	839.1	966.7
Waxed	0.1	52.6	38.8	465.5	536.4
MoS₂	0.12	63.2	46.6	559.4	644.5
Galvanized	0.25	131.6	97.1	1164.8	1342.0

Stress area: 167.25 mm² · Proof load: 46,830 N · Clamp load (75%): 35,122 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	112.4	82.9	994.8	1146.2
Oiled	0.15	84.3	62.2	746.1	859.6
Zinc Plated	0.18	101.2	74.6	895.7	1032.0
Waxed	0.1	56.2	41.5	497.4	573.1
MoS₂	0.12	67.4	49.7	596.5	687.3
Galvanized	0.25	140.5	103.6	1243.5	1432.7

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 280 MPa × 156.67 mm² = 32,901 N

Step 2 — Torque (dry): T = 0.20 × 0.0160 m × 32,901 N = 105.3 N·m

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

Moderate-duty industrial applications, machinery guards, medium-strength connections

• 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

Class5.6

Diameter16 mm

Pitch (coarse)2.0 mm

Tensile500 MPa

Yield300 MPa

Proof280 MPa