M16 Grade 4.8 Torque Specification

Torque Values by Surface Condition

Stress area: 156.67 mm² · Proof load: 48,568 N · Clamp load (75%): 36,426 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	116.6	86.0	1032.0	1189.0
Oiled	0.15	87.4	64.5	773.6	891.2
Zinc Plated	0.18	104.9	77.4	928.4	1069.7
Waxed	0.1	58.3	43.0	516.0	594.5
MoS₂	0.12	69.9	51.6	618.7	712.8
Galvanized	0.25	145.7	107.5	1289.6	1485.7

Stress area: 167.25 mm² · Proof load: 51,848 N · Clamp load (75%): 38,886 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	124.4	91.8	1101.0	1268.5
Oiled	0.15	93.3	68.8	825.8	951.4
Zinc Plated	0.18	112.0	82.6	991.3	1142.1
Waxed	0.1	62.2	45.9	550.5	634.3
MoS₂	0.12	74.7	55.1	661.2	761.7
Galvanized	0.25	155.5	114.7	1376.3	1585.7

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 310 MPa × 156.67 mm² = 36,426 N

Step 2 — Torque (dry): T = 0.20 × 0.0160 m × 36,426 N = 116.6 N·m

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

Light structural connections, furniture assembly, non-load-bearing joints

• 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

Class4.8

Diameter16 mm

Pitch (coarse)2.0 mm

Tensile420 MPa

Yield340 MPa

Proof310 MPa