M36 Grade 5.8 Torque Specification

Torque Values by Surface Condition

Stress area: 816.72 mm² · Proof load: 310,354 N · Clamp load (75%): 232,765 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	1675.9	1236.1	14833.0	17089.5
Oiled	0.15	1256.9	927.0	11124.5	12816.9
Zinc Plated	0.18	1508.3	1112.5	13349.6	15380.4
Waxed	0.1	838.0	618.1	7416.9	8545.3
MoS₂	0.12	1005.5	741.6	8899.4	10253.3
Galvanized	0.25	2094.9	1545.1	18541.4	21362.1

Stress area: 864.95 mm² · Proof load: 328,681 N · Clamp load (75%): 246,511 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	1774.9	1309.1	15709.2	18099.0
Oiled	0.15	1331.2	981.8	11782.1	13574.5
Zinc Plated	0.18	1597.4	1178.2	14138.2	16289.0
Waxed	0.1	887.4	654.5	7854.2	9049.0
MoS₂	0.12	1064.9	785.4	9425.2	10859.0
Galvanized	0.25	2218.6	1636.4	19636.3	22623.5

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 380 MPa × 816.72 mm² = 232,765 N

Step 2 — Torque (dry): T = 0.20 × 0.0360 m × 232,765 N = 1675.9 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.

SizeM36

Class5.8

Diameter36 mm

Pitch (coarse)4.0 mm

Tensile520 MPa

Yield420 MPa

Proof380 MPa