Longze Hot Dip Galvanized (HDG) Hex Nuts are premium-grade internal fasteners engineered for extreme durability in the most challenging outdoor environments. Manufactured to rigorous ISO 4032, DIN 934, and ASTM A563 standards, these nuts undergo a specialized molten zinc bath process at 450°C to create a powerful metallurgical bond that prevents rust and degradation in coastal and industrial zones.
To ensure seamless installation, our HDG nuts feature precision oversized tapping. This critical design adjustment accounts for the thick zinc coating on matching HDG bolts (40–65 microns), eliminating the risk of thread seizing or "frozen" joints while maintaining maximum structural integrity for heavy-duty infrastructure projects.
Detailed Parameters
| Technical Standards | ISO 4032, DIN 934, ASTM A563 | Metric Size Range | M6 to M64 (6mm to 64mm) |
|---|---|---|---|
| Imperial Size Range | 1/4" to 2-1/2" (0.250" to 2.500") | Property Classes | Grade 8, Grade 10 / ASTM Gr. A, DH |
| Thread Type | Coarse (UNC) / Fine (UNF) - Oversized | Coating Thickness | Average 40μm to 65μm |
| Material Base | Medium Carbon / Alloy Steel | Zinc Process | Centrifuged Hot Dip Galvanizing |
| Proof Load (Min) | Up to 1060 MPa (Grade 10) | Certification | ISO 9001 Quality Management |
Key Advantages
Extreme Corrosion Shield
Thicker metallurgical zinc layers provide decades of maintenance-free service in high-humidity and salt-air environments.
Self-Healing Protection
The sacrificial zinc anode protects exposed steel from rust even if the coating is scratched during installation.
Precision Over-Tapping
Engineered thread clearance prevents seizing and ensures a smooth fit with HDG bolts without stripping.
High Structural Strength
Designed to pair with Grade 8.8 or ASTM A325 bolts, making the nut the strongest point in the assembly.
Mechanical Durability
Iron-zinc alloy layers are highly resistant to mechanical damage and abrasion compared to standard plating.
Strict QC Gaging
Every batch is verified via Go/No-Go thread gauges and magnetic induction for zinc thickness compliance.
Product Gallery
Management Platforms
Power Infrastructure
Ideal for securing high-voltage transmission towers and telecommunication masts.
Bridge Engineering
Used in fastening guardrails, light poles, and structural steel beams for highways.
Solar Energy Systems
Heavy-duty support structures for large-scale solar arrays in rural outdoor areas.
Marine Facilities
Critical for piers, docks, and coastal boardwalks facing constant salt-air exposure.
Export Packaging
Available in 25kg woven bags, steel drums, or reinforced pallets for global shipping.
Quality Assurance
Full ASTM A153 and ISO 1461 compliance verified by magnetic induction testing.
Investment Return Comparison
| Coating Method | Service Life (Harsh Env) | Maintenance Cost |
|---|---|---|
| Electro-Plated Zinc | 1 - 3 Years | High (Frequent Replacement) |
| Mechanical Galv | 3 - 7 Years | Medium (Periodic Check) |
| Standard HDG | 15 - 25 Years | Low (Long-term Stability) |
| HDG + Wax Lubricant | 25+ Years | Very Low (Easy Tensioning) |
| Stainless Steel | Variable (Pitting Risk) | Medium (Material Cost) |
Frequently Asked Questions
HDG nuts are "Oversized Tapped" to accommodate the thick zinc coating of HDG bolts. If used on standard bolts, the gap is too wide, which reduces the joint's stripping strength.
No, it is not recommended. Pairing HDG carbon steel with stainless steel can cause galvanic corrosion, leading to premature degradation of the zinc coating.
Never re-tap an HDG nut. This process removes the protective zinc layer from the threads, leaving the steel exposed to rapid corrosion.
HDG creates a thick metallurgical bond through a molten bath, providing significantly higher corrosion resistance than the thin layer produced by electro-plating.
We use magnetic induction testing on every batch to ensure compliance with international standards like ASTM A153 or ISO 1461.
We offer a full range of Metric sizes from M6 to M64 and Imperial sizes from 1/4" to 2-1/2" to support global infrastructure projects.
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