M10 Grade 9.8 Torque Specification

Torque Values by Surface Condition

Stress area: 58.0 mm² · Proof load: 37,700 N · Clamp load (75%): 28,275 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	56.6	41.7	501.0	577.2
Oiled	0.15	42.4	31.3	375.3	432.4
Zinc Plated	0.18	50.9	37.5	450.5	519.0
Waxed	0.1	28.3	20.9	250.5	288.6
MoS₂	0.12	33.9	25.0	300.0	345.7
Galvanized	0.25	70.7	52.1	625.7	720.9

Stress area: 61.2 mm² · Proof load: 39,780 N · Clamp load (75%): 29,835 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	59.7	44.0	528.4	608.8
Oiled	0.15	44.8	33.0	396.5	456.8
Zinc Plated	0.18	53.7	39.6	475.3	547.6
Waxed	0.1	29.8	22.0	263.8	303.9
MoS₂	0.12	35.8	26.4	316.9	365.1
Galvanized	0.25	74.6	55.0	660.3	760.7

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 650 MPa × 58.0 mm² = 28,275 N

Step 2 — Torque (dry): T = 0.20 × 0.0100 m × 28,275 N = 56.6 N·m

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

Heavy-duty automotive, high-performance machinery (limited availability, mostly M16 and smaller)

• 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.

SizeM10

Class9.8

Diameter10 mm

Pitch (coarse)1.5 mm

Tensile900 MPa

Yield720 MPa

Proof650 MPa