M16 Grade 4.6 Torque Specification

Torque Values by Surface Condition

Stress area: 156.67 mm² · Proof load: 35,251 N · Clamp load (75%): 26,438 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	84.6	62.4	748.8	862.7
Oiled	0.15	63.5	46.8	562.0	647.5
Zinc Plated	0.18	76.1	56.1	673.5	776.0
Waxed	0.1	42.3	31.2	374.4	431.3
MoS₂	0.12	50.8	37.5	449.6	518.0
Galvanized	0.25	105.8	78.0	936.4	1078.9

Stress area: 167.25 mm² · Proof load: 37,631 N · Clamp load (75%): 28,223 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	90.3	66.6	799.2	920.8
Oiled	0.15	67.7	49.9	599.2	690.4
Zinc Plated	0.18	81.3	60.0	719.6	829.0
Waxed	0.1	45.2	33.3	400.1	460.9
MoS₂	0.12	54.2	40.0	479.7	552.7
Galvanized	0.25	112.9	83.3	999.2	1151.3

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 225 MPa × 156.67 mm² = 26,438 N

Step 2 — Torque (dry): T = 0.20 × 0.0160 m × 26,438 N = 84.6 N·m

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

Non-critical assemblies, light-duty applications, general-purpose hardware where high strength is not required

• 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

Class4.6

Diameter16 mm

Pitch (coarse)2.0 mm

Tensile400 MPa

Yield240 MPa

Proof225 MPa