M36 Grade 4.8 Torque Specification

Torque Values by Surface Condition

Stress area: 816.72 mm² · Proof load: 253,183 N · Clamp load (75%): 189,887 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	1367.2	1008.4	12100.7	13941.6
Oiled	0.15	1025.4	756.3	9075.6	10456.2
Zinc Plated	0.18	1230.5	907.6	10890.8	12547.7
Waxed	0.1	683.6	504.2	6050.4	6970.8
MoS₂	0.12	820.3	605.0	7260.3	8364.8
Galvanized	0.25	1709.0	1260.5	15125.9	17427.0

Stress area: 864.95 mm² · Proof load: 268,134 N · Clamp load (75%): 201,101 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	1447.9	1067.9	12815.0	14764.5
Oiled	0.15	1085.9	800.9	9611.0	11073.1
Zinc Plated	0.18	1303.1	961.1	11533.4	13288.0
Waxed	0.1	724.0	534.0	6407.9	7382.8
MoS₂	0.12	868.8	640.8	7689.5	8859.3
Galvanized	0.25	1809.9	1334.9	16019.0	18455.9

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 310 MPa × 816.72 mm² = 189,887 N

Step 2 — Torque (dry): T = 0.20 × 0.0360 m × 189,887 N = 1367.2 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.

SizeM36

Class4.8

Diameter36 mm

Pitch (coarse)4.0 mm

Tensile420 MPa

Yield340 MPa

Proof310 MPa