ISO 3266 specifies design requirements for forged steel eyebolts used in lifting. It defines load ratings at various angles from the bolt axis.

How does angle affect eyebolt capacity?

Eyebolts loaded at angles have significantly reduced capacity. At 45° the capacity may be only 25% of the axial rating. Only swivel eyebolts should be used at angles.

Can regular eyebolts be loaded at an angle?

No. Standard (non-swivel) eyebolts should only be loaded axially (0°). Angular loading creates bending that can cause failure. Use swivel-type eyebolts for angular loads.

What safety factor do eyebolts use?

ISO 3266 eyebolts have a safety factor of 4:1 (MBL = 4 × WLL). This is standard for forged lifting hardware.

How do I mark eyebolts per ISO 3266?

Eyebolts must be marked with: WLL, manufacturer's mark, material grade, and the standard number (ISO 3266). Proof load testing is required.

Free Engineering Tool #218

Eyebolt Load Calculator — ISO 3266

Calculate reduced eyebolt capacity at angular loading per ISO 3266. Enter rated WLL and lift angle.

ISO 3266Angular LoadingSwivel Eyebolts

Results

Reduced WLL at Angle

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Reduction Factor

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MBL (4:1 SF)

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ISO 3266 Angular Load Factors

Angle from bolt axis	Factor	% of WLL
0° (axial)	1.00	100%
15°	0.75	75%
30°	0.50	50%
45°	0.25	25%

⚠️ Important: Standard (non-swivel) eyebolts must ONLY be loaded axially. Angular factors apply only to swivel-type eyebolts per ISO 3266.

Eyebolt Load Calculator | ISO 3266 | Reduced Capacity at Angle

Published by Nikolai Shelkovenko on February 15, 2026 February 15, 2026

Results

ISO 3266 Angular Load Factors