Product Summary

Longze Heavy-Duty Lifting Eye Bolts are high-strength forged fasteners designed as reliable attachment points for hoisting heavy machinery, motors, and control cabinets.

Manufactured in Yongnian, China, our eye bolts undergo a rigorous drop-forging process to ensure consistent grain structure and superior load-bearing capacity. Whether for

permanent installation in industrial gearboxes or temporary rigging in construction, Longze eye bolts provide the safety factor required for secure vertical and angular lifts.

• ✔ Integrated Forged Design: The ring and shank are forged as a single piece to eliminate stress concentrations and prevent head separation under tension.

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• ✔ High-Precision Threading: Fully threaded shanks are machined to 6g/2A tolerances, ensuring easy installation into tapped holes without binding.

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• ✔ Certified Safety Factor: Engineered with a minimum 5:1 safety factor (Breaking Load to WLL) to comply with international rigging safety protocols.

• Standards: DIN 580, ISO 3266, ASME B30.26.

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• Diameter Range: M6 to M64 | 1/4" to 2-1/2".

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• Shank Length: Standard DIN lengths or custom extended shanks for deep-hole applications.

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• Material Grade: Carbon Steel C15E | Stainless Steel 304 (A2-70) & 316 (A4-80).

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• Surface Finish: Zinc Plated, Hot Dip Galvanized (HDG), Self-Color, Mirror Polished (SS).

Mechanical Properties & Material Standards

• Matching the steel grade to the structural requirements of the transmission line.

• Material Grade	Tensile Strength	Yield Strength	Hardness	Environmental Suitability
  C15E (Carbon)	410 - 540 MPa	245 MPa	110 - 150 HB	General Machinery / Motors
  SS304 (A2)	700 MPa	450 MPa	200 - 280 HV	Food Processing / Cleanroom
  SS316 (A4)	800 MPa	600 MPa	240 - 320 HV	Marine / Chemical / Coastal

Standard Cross Arm Dimensions

• Common angle steel configurations for standard utility pole mounting.

• Thread Size (D)	Shank Length (L)	Eye ID (d1)	Base Dia (d2)	Vertical WLL (kg)
  M10 (3/8")	17 mm	25 mm	25 mm	230 kg
  M12 (1/2")	20.5 mm	30 mm	30 mm	340 kg
  M16 (5/8")	27 mm	35 mm	35 mm	700 kg
  M20 (3/4")	30 mm	40 mm	40 kg	1200 kg

Galvanizing & Corrosion Resistance

• Ensuring 30+ years of service life in corrosive environments.

• Surface Treatment	Coating Thickness	Salt Spray Test	Service Life	แอปพลิเคชัน
  Zinc Plated	8 - 12 μm	72 - 120 Hours	High	Indoor Industrial
  Hot Dip Galv.	≥ 50 μm	500 - 800 Hours	Maximum	Outdoor Power Grids
  SS316 Polished	N/A	1000+ Hours	Extreme	Marine / Coastal

Avoid Pitfalls:

• Bending Stress on Shank: We ensure the shoulder of the eye bolt is perfectly flat and perpendicular to the shank. This allows for full contact with the base material, preventing the shank from bending or snapping during side-angled lifts.

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• Inferior Casting vs. Forging: Cast eye bolts are strictly for decorative use. Longze utilizes Closed-Die Forging for all DIN 580 bolts, providing a ductile material that can withstand sudden impact loads without shattering.

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• Inadequate Thread Depth: We recommend a minimum thread engagement of 1x diameter in steel and 2x diameter in aluminum. Our precision threads ensure maximum shear resistance in the tapped hole.

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Perfect Fit Assembly:

• Washer Compatibility: For applications with uneven surfaces, pair our eye bolts with Hardened Washers to ensure a flush, perpendicular seat.

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• Custom Shank Lengths: In the power industry, standard shanks are often too short. We can manufacture custom DIN 580 bolts with extra-long shanks for securing thick-walled housings.

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Quality Control & Logistics:

• ISO 9001 Certified: 5-step QC including batch-wise destructive testing, thread Go/No-Go verification, and 100% visual inspection of the forged ring.

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• Sea-Worthy Packaging: Bolts are individually bagged or partitioned to prevent thread damage, then packed in reinforced cartons on international-standard pallets.

• Q: Can I use these for lifting at a 90-degree angle? A: DIN 580 bolts are primarily for vertical lifting. For 90-degree side-pulling, the WLL is significantly reduced. We recommend using our Swivel Hoist Rings for constant side-loading.

• Q: Do you offer MBL (Minimum Breaking Load) certificates? A: Yes, we provide Mill Test Certificates (MTR) showing the breaking load, which is 5x the WLL for all our forged eye bolts.