Free Engineering Tool #218
Eyebolt Load Calculator — ISO 3266
Calculate the maximum working load of ISO 3266 grade 4 forged eyebolts — axial (single eyebolt) or inclined loading as a pair (0–45°). Enter rated WLL and loading configuration.
Results
ISO 3266 Inclined-Loading Rules (Table 4)
ISO 3266 covers forged steel eyebolts grade 4. A single eyebolt is rated at its marked WLL for axial loading only. Inclined loading is rated only for a pair of eyebolts: the maximum working load of the pair is 1.4 × WLL of one eyebolt for angles 0° < β ≤ 45°, with the plane of each eye aligned within ±5° of the lifting plane.
| Loading configuration | Factor | Maximum working load |
|---|---|---|
| Single eyebolt, axial (β = 0°) | 1.00 | 100% of WLL |
| Pair of eyebolts, inclined 0° < β ≤ 45° | 1.40 (pair) | 1.4 × WLL for the pair (≈ 0.7 × WLL per eyebolt) |
| Any configuration, β > 45° | — | Not permitted |
⚠️ Important: A single eyebolt must only be loaded along its axis. ISO 3266 permits inclined loading only for a pair of eyebolts with correctly aligned eye planes (use shims if needed — never over-tighten). Stepped single-eyebolt reduction tables such as 75% / 50% / 25% at 15° / 30° / 45° come from manufacturer catalogues for swivel or pivoting eyebolts, not from ISO 3266 — always verify the rating on the manufacturer’s certificate for the specific eyebolt.
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Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
