M16 Grade 5.8 Torque Specification

Torque Values by Surface Condition

Stress area: 156.67 mm² · Proof load: 59,535 N · Clamp load (75%): 44,651 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	142.9	105.4	1264.8	1457.2
Oiled	0.15	107.2	79.1	948.8	1093.1
Zinc Plated	0.18	128.6	94.9	1138.2	1311.4
Waxed	0.1	71.4	52.7	631.9	728.1
MoS₂	0.12	85.7	63.2	758.5	873.9
Galvanized	0.25	178.6	131.7	1580.7	1821.2

Stress area: 167.25 mm² · Proof load: 63,555 N · Clamp load (75%): 47,666 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	152.5	112.5	1349.7	1555.1
Oiled	0.15	114.4	84.4	1012.5	1166.6
Zinc Plated	0.18	137.3	101.3	1215.2	1400.1
Waxed	0.1	76.3	56.3	675.3	778.0
MoS₂	0.12	91.5	67.5	809.8	933.0
Galvanized	0.25	190.7	140.7	1687.8	1944.6

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 380 MPa × 156.67 mm² = 44,651 N

Step 2 — Torque (dry): T = 0.20 × 0.0160 m × 44,651 N = 142.9 N·m

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

General industrial fastening, equipment mounting, moderate structural loads

• 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

Class5.8

Diameter16 mm

Pitch (coarse)2.0 mm

Tensile520 MPa

Yield420 MPa

Proof380 MPa