Overview
ISO 3266:2010 - Forged steel eyebolts grade 4 for general lifting purposes defines the essential characteristics, performance requirements and critical dimensions for one-piece forged steel eyebolts used in general lifting operations. The standard ensures interchangeability and compatibility with other lifting components, permitting both axial and inclined loading and direct connection with shackles and certain sling hooks of equivalent working load limit.
Key scope points:
- Applies to forged, one-piece eyebolts grade 4 manufactured after publication.
- Suitable for service temperatures from −20 °C to 200 °C.
- Covers safety aspects, mechanical performance, dimensions, testing and marking.
Key technical topics and requirements
ISO 3266:2010 specifies technical requirements that manufacturers and users must follow to ensure safe, compatible eyebolts:
- Dimensions & tolerances: Critical eye dimensions (internal diameter E, cross‑section F, collar B, shank/thread geometry) are defined to enable direct connection with shackles (ISO 2415) and some sling hooks.
- Threading: Shank threads follow ISO 261 (coarse pitch) and ISO 965‑1 tolerance class 6g.
- Material & metallurgy: Steel must be suitable for forging and heat treatment; sulfur and phosphorus content limits are specified and fine‑grain practice is required.
- Heat treatment & hardness: Forgings must be hardened/tempered or normalized after forging; tempering minimum 475 °C. Maximum hardness: 214 HBW (or 96 HRB).
- Mechanical performance: Proof force, minimum breaking force and deformation tests for inclined loading are defined; Charpy V‑notch impact tests require a minimum average of 27 J at −20 °C.
- Workmanship: Eyebolts must be forged in one piece, with machined collar faces and correct thread run‑out radii.
- Testing & traceability: Type tests, manufacturing tests, marking and a traceability code are required to link each eyebolt to its manufacturing history.
- Safety: Clause with significant hazards and guidance for selection, care and use (Annex A).
Practical applications and users
ISO 3266:2010 is used wherever safe, standardized lifting attachments are required:
- Manufacturers of forged lifting components and eyebolts (design, production, QA)
- Lifting equipment designers and rigging engineers specifying compatible connectors
- Procurement and quality inspectors ensuring compliance with working load limits (WLL)
- Plant safety officers, maintenance and rigging personnel selecting and inspecting eyebolts for cranes, hoists, slings and lifting assemblies
Benefits: improved safety, component interchangeability, clear acceptance/testing criteria and traceability for lifting operations.
Related standards
Relevant normative and related documents include:
For manufacturers and specifiers, ISO 3266:2010 provides a practical, safety‑focused framework to produce and select forged steel eyebolts grade 4 suitable for general lifting purposes.