Product Summary

Longze Lifting Eye Bolts are drop-forged for maximum load-bearing security in overhead rigging and industrial anchoring. Fully compliant with DIN 580 en ISO 3266, these bolts feature a 4:1

Safety Factor, providing the certified reliability required for motor housings, transformer lifting, en heavy machinery transport.

• ✔ Structural Integrity: One-piece drop-forging ensures a continuous grain flow, eliminating the risk of ring separation under high stress.

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• ✔ Material Precision: Available in high-tensile C15E Carbon Steel of SS316 Stainless Steel for extreme acid and salt-water resistance.

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• ✔ Certified Safety: Every batch undergoes Proof Load Testing to ensure it meets or exceeds the rated Working Load Limit (WLL).

• Standards: DIN 580, ISO 3266, ASME B18.15.

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• Size Range: M6 to M100 | 1/4” to 4” (Full metric & imperial stock).

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• Property Class: Grade 8.8, C15E, A2-70, A4-80.

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• Surface Finish: Hot-Dip Galvanized (HDG), Zinc Plated, Electropolished.

Mechanical Properties & Material Hardness

• Matching the certified tensile strength and hardness ratings for industrial safety.

• Material Grade	Tensile Strength (Rm)	Yield Strength (Re)	Hardness (HB/HV)
  Carbon Steel 4.8	≥ 400 MPa	≥ 320 MPa	120 - 160 HB
  Carbon Steel 8.8	≥ 800 MPa	≥ 640 MPa	250 - 320 HV
  Stainless Steel 304	≥ 500 MPa	≥ 210 MPa	≤ 200 HV
  Stainless Steel 316	≥ 520 MPa	≥ 210 MPa	≤ 200 HV

Surface Treatment & Corrosion Resistance

• Selecting the appropriate coating for diverse industrial environments.

• Coating Type	Process	Salt Spray Test	Best Application
  Hot-Dip Galv. (HDG)	Molten Zinc	500 - 800 Hours	Outdoor / Coastal
  Zinc Plated	Electrolytic	72 - 144 Hours	Indoor Structural
  Black Oxide	Chemical	< 48 Hours	Internal Machinery
  Electropolished	Chemical	1000+ Hours	Marine / Chemical

Dimensions & Global Size Conversion

• Technical Standard: Longze provides heavy-duty lifting solutions supporting both Metric (DIN/ISO) and Imperial (ASME) standards. Use this integrated conversion table to identify the correct thread size and Working Load Limit (WLL) for your international rigging projects.

• American Size (Inch)	Nearest Metric Size (M)	Thread Diameter (mm/inch)	Eye Inner Dia. (mm/inch)	WLL - Vertical (kg/lbs)
  1/4" - 20	M6	6.35 mm / 0.250"	16.0 mm / 0.630"	70 kg / 150 lbs
  5/16" - 18	M8	7.94 mm / 0.312"	20.0 mm / 0.787"	140 kg / 300 lbs
  3/8" - 16	M10	9.53 mm / 0.375"	25.0 mm / 0.984"	230 kg / 500 lbs
  1/2" - 13	M12	12.70 mm / 0.500"	30.0 mm / 1.181"	340 kg / 750 lbs
  5/8" - 11	M16	15.88 mm / 0.625"	35.0 mm / 1.378"	700 kg / 1,500 lbs
  3/4" - 10	M20	19.05 mm / 0.750"	40.0 mm / 1.575"	1,200 kg / 2,600 lbs
  1" - 8	M24	25.40 mm / 1.000"	50.0 mm / 1.969"	1,800 kg / 4,000 lbs
  1-1/4" - 7	M30	31.75 mm / 1.250"	60.0 mm / 2.362"	3,200 kg / 7,000 lbs

Avoid Pitfalls:

• Angular Loading: Die Working Load Limit (WLL) of a DIN 580 eye bolt significantly reduces if the load is not perfectly vertical. Never exceed a 45-degree angle without a specific technical review.

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• Shoulder Seating: The shoulder of the eye bolt must be 100% flush against the mating surface. Any gap creates a leverage point that can lead to bolt fracture under stress.

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• Over-Tightening: Do not use a bar through the eye to over-torque the bolt. Hand-tight is often sufficient unless a specific torque is required for pre-loading.

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Perfect Fit Assembly:

• Thread Engagement: Ensure the receiving hole has a depth of at least 1.5x the bolt diameter to ensure the threads can hold the rated capacity.

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• Orientation: When using two eye bolts for a bridle lift, align the eyes so they are in the same plane to prevent "twisting" forces on the ring.

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Quality Control & Logistics:

• ISO 9001 Certified: 5-step QC insluitend Proof Load Testing, Ultrasonic Flaw Detection, en Thread Go/No-Go Gauge verification.

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• Sea-Worthy Packaging: Fumigation-free pallets, wooden cases, cartons with inner plastic bags, 25kg cartons. Secured for maritime export from our Yongnian hub.

• Q: Can I use these for permanent outdoor rigging? A: Yes, but we highly recommend Hot-Dip Galvanized of SS316 for any outdoor application to prevent rust and hydrogen embrittlement.

• Q: Are these certified for human overhead lifting? A: Longze eye bolts meet ISO 3266 industrial standards. Always check local safety regulations for specific "man-rated" lifting requirements.