M27 Grade 5.6 Torque Specification

Torque Values by Surface Condition

Stress area: 459.41 mm² · Proof load: 128,635 N · Clamp load (75%): 96,476 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	521.0	384.3	4611.2	5312.7
Oiled	0.15	390.7	288.2	3458.0	3984.0
Zinc Plated	0.18	468.9	345.8	4150.1	4781.5
Waxed	0.1	260.5	192.1	2305.6	2656.4
MoS₂	0.12	312.6	230.6	2766.7	3187.6
Galvanized	0.25	651.2	480.3	5763.6	6640.4

Stress area: 496.18 mm² · Proof load: 138,930 N · Clamp load (75%): 104,198 N

Surface Condition	K Factor	N·m	ft·lbs	in·lbs	kgf·cm
Plain/Dry	0.2	562.7	415.0	4980.3	5738.0
Oiled	0.15	422.0	311.3	3735.0	4303.2
Zinc Plated	0.18	506.4	373.5	4482.0	5163.9
Waxed	0.1	281.3	207.5	2489.7	2868.5
MoS₂	0.12	337.6	249.0	2988.0	3442.6
Galvanized	0.25	703.3	518.7	6224.7	7171.7

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 280 MPa × 459.41 mm² = 96,476 N

Step 2 — Torque (dry): T = 0.20 × 0.0270 m × 96,476 N = 521.0 N·m

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

Moderate-duty industrial applications, machinery guards, medium-strength connections

• 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.

SizeM27

Class5.6

Diameter27 mm

Pitch (coarse)3.0 mm

Tensile500 MPa

Yield300 MPa

Proof280 MPa