DIN 580 Forged Lifting Eye Bolt A4-70 Marine
DIN 580 Forged Lifting Eye Bolt — A4-70 Stainless Steel, M6–M20
TheDIN 580 lifting eye bolt is a one-piece forged fastener with a threaded shank and an integral closed ring at the head, designed specifically for vertical and angular lifting operations on ships and offshore structures. Unlike standard hex bolts that require separate shackles or hooks, the DIN 580 eye bolt provides a ready-made lifting attachment point for slings, wire ropes, chains, and carabiner hooks. Every lifting eye bolt is stamped with its working load limit (WLL) and manufacturer identification directly on the ring — a field-visible load rating that is mandatory for shipboard lifting safety.
sinofastener supplies DIN 580 forged lifting eye bolts in A4-70 (316 stainless steel), covering sizes M6 through M20. The forged austenitic structure of A4-70 combines deep corrosion resistance with the ductility needed to absorb shock loads without brittle fracture — essential for deck-mounted lifting points exposed to salt spray, engine room hoisting, and offshore rigging.
DIN 580 vs DIN 444: Which Eye Bolt for Which Job
| Feature | DIN 580 (Lifting Eye Bolt) | DIN 444 (Rigging Eye Bolt) |
|---|---|---|
| Design | Forged with shoulder under the ring — ring sits flush on the mounting surface | Forged without shoulder — ring sits above the mounting surface |
| Load Direction | Vertical lift and angular loads (with shoulder bearing against surface) | In-line axial loads only — angular loads risk ring bending |
| Primary Use | Lifting operations — machinery hoisting, equipment installation, engine room maintenance | Non-lifting rigging — lashing, tie-down, cargo securing, mooring backup points |
| WLL Marking | Mandatory — WLL + size + manufacturer ID stamped on ring | Optional — typically not load-stamped |
| Angular Load Safety | Shoulder prevents ring bending at lift angles up to 45° | Not suitable for angular loading — ring can deform |
Working Load Limits per DIN 580
| Thread Size | WLL (Vertical Lift, 0°) | WLL at 45° Angle |
|---|---|---|
| M6 | 0.07 t | 0.04 t |
| M8 | 0.14 t | 0.08 t |
| M10 | 0.23 t | 0.14 t |
| M12 | 0.36 t | 0.21 t |
| M16 | 0.70 t | 0.42 t |
| M20 | 1.20 t | 0.72 t |
Note: WLL values are per DIN 580 standard. Angular load capacity is approximately 60% of vertical WLL. Always derate for lift angles exceeding 45°. Consult DIN 580 full tables for intermediate sizes.
Why A4-70 (316) for Marine Lifting Applications
- Molybdenum content (2.0–3.0%) provides superior resistance to pitting and crevice corrosion in chloride-rich marine atmospheres
- Forged grain structure eliminates internal voids and weak points that cast or welded eye assemblies suffer from
- Austenitic ductility absorbs shock loads during lifting without brittle fracture — critical when hoisting engine room machinery or deck equipment
- Passivated surface (per ASTM A967) restores the chromium oxide layer after machining, ensuring sustained corrosion resistance
Critical Installation Requirements
| Rule | Reason |
|---|---|
| Shoulder must sit flush | Any gap between shoulder and mounting surface reduces angular load capacity and risks ring bending under side load |
| Use hardened washer if surface is uneven | Compensates for surface irregularities to ensure full shoulder bearing |
| Torque to full thread engagement | Insufficient engagement risks thread stripping under load; use minimum 1.0× diameter thread engagement in steel |
| Never paint over WLL stamping | Load marking must remain visible for pre-lift inspection — required by lifting equipment regulations |
| Inspect for cracks before each use | Forged eye bolts in service must be checked for ring deformation, thread damage, and corrosion pitting |
Marine Applications
- Engine Room — lifting eyes on machinery foundations for pump, motor, and heat exchanger removal during maintenance
- Deck Equipment Hoisting — temporary eye bolts for crane-assisted installation of winches, capstans, and davits
- Cargo Lashing Points — fixed lifting eyes on deck for container and spare parts crate securing
- Workboat and Tender Decks — mooring bollard backup points and lifting eyes for equipment deployment
- Offshore Platforms — rigging attachment points on subsea equipment skids and module lifting
Supply and Certification
All DIN 580 eye bolts are hot-forged from a single piece — never welded or fabricated — to eliminate weak points at the shank-to-ring junction. Material certificates provided per EN 10204 3.1. Third-party inspection (Lloyd's Register, DNV, Bureau Veritas) coordinated on request for lifting appliance registration. Annual capacity 50,000 tonnes. sinofastener — 36 years of fastener manufacturing.
Material: A4-70 (316) Stainless Steel (passivated per ASTM A967)
Standard: DIN 580
Size Range: M6 – M20
WLL Range: 0.07t – 1.20t (vertical lift)
Thread: Metric coarse, tolerance 6g
Marking: WLL + size + manufacturer ID stamped on ring
E-mail: sales@sinofastener.com | SINOFASTENER
