Product Summary

Longze Hot Dip Galvanized (HDG) Hex Nuts are high-durability internal fasteners manufactured to ISO 4032, DIN 934, Und ASTM A563 standards. Specifically engineered for heavy-duty outdoor infrastructure,

these Longze HDG Hex Nuts undergo a molten zinc bath process at approximately 450°C, creating a thick, metallurgical bond. To accommodate the significant thickness of the galvanized coating on mating bolts,

these nuts are Oversized Tapped (over-tapped) to ensure a smooth, secure fit without compromising structural integrity.

• ✔ Extreme Corrosion Protection: The HDG coating is significantly thicker than standard zinc plating, providing decades of maintenance-free service in coastal, industrial, and high-humidity environments.

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• ✔ Precision Oversized Tapping: Threads are tapped slightly larger than standard to account for the 40–65 micron zinc layer on HDG bolts, preventing seizing or "frozen" threads.

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• ✔ High-Strength Structural Bonding: Designed to pair perfectly with Grade 8.8 or ASTM A325 structural bolts, ensuring the nut is the strongest point in the assembly.

Product Highlight: Engineered for harsh environments, Longze HDG nuts provide a high-strength, superior alternative to standard electro-plated fasteners in utility and bridge construction projects.

 

• Metallurgical Zinc Bond – Unlike plating, the HDG process creates an iron-zinc alloy layer that is extremely resistant to mechanical damage and abrasion during installation.

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• Self-Healing Properties – If the coating is scratched, the surrounding zinc acts as a sacrificial anode, protecting the exposed steel from rust.

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• Strict Thread Clearance – Every nut is gauged after tapping to ensure it meets the specific "over-tap" allowance required for HDG compatibility.

Technical Standard: Manufactured to strict international tolerances, Longze supports a full range of Metric (M6 - M64) and Imperial (1/4" - 2-1/2") sizes, ensuring 100% compatibility across all property classes.

 

• Standards: ISO 4032, DIN 934 (Metric), ASTM A563 (American/Inch)

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• Metric Size Range: M6 to M64 (Diameter 6mm to 64mm)

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• Inch Size Range: 1/4" to 2-1/2" (Diameter 0.250" to 2.500")

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• Property Class: Grade 8, Grade 10 (Metric) / Grade A, DH (ASTM)

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• Thread Type: Coarse (UNC) / Fine (UNF) - Oversized Tapped

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• Coating Thickness: 40μm to 65μm (Average)

Material & Mechanical Properties

• Engineering Note: Structural integrity depends on the correct property class. We offer a full material range to meet your specific tensile strength and proof load requirements.

• Property Class	Material	Proof Load (min)	Feature
  Grade 8	Medium Carbon Steel	800 - 920 MPa	Standard Structural Use
  Grade 10	Alloy Steel	1000 - 1060 MPa	High-Strength Machinery
  ASTM A563 Gr. A	Low/Med Carbon	60,000 psi	General Utility Hardware
  ASTM A563 Gr. DH	Heat Treated Carbon	175,000 psi	Heavy Structural / Bridges

Dimensions & Global Size Conversion

• Metric to Inch Comparison: Use this integrated conversion table to identify the exact specifications required for your international project. Longze HDG nuts are oversized specifically to match HDG bolts.

• American Size (Inch)	Nearest Metric Size (M)	Width Across Flats (s)	Nut Height (m)	Oversize Allowance
  1/4" - 20	M6	10.0 mm / 0.437"	5.2 mm / 0.226"	+0.35 mm
  3/8" - 16	M10	16.0 mm / 0.562"	8.4 mm / 0.337"	+0.40 mm
  1/2" - 13	M12	18.0 mm / 0.750"	10.8 mm / 0.448"	+0.45 mm
  5/8" - 11	M16	24.0 mm / 0.937"	14.8 mm / 0.559"	+0.50 mm
  3/4" - 10	M20	30.0 mm / 1.125"	18.0 mm / 0.665"	+0.50 mm
  1" - 8	M24	36.0 mm / 1.500"	21.5 mm / 0.887"	+0.60 mm

Surface Treatment

• Procurement Guide: Surface finish determines service life. Longze provides specialized hot-dip coatings to ensure maximum corrosion resistance and aesthetic consistency for any environment.

• Finish	Coating Method	Salt Spray	Anwendung
  Standard HDG	Centrifuged Hot Dip	500 - 1000h	Transmission Towers / Fencing
  Mechanical Galv	Cold Impact	300 - 500h	High-Precision Moving Parts
  HDG + Wax	Lubricated Dip	1000h+	High-Torque Structural Tensioning