Custom Leaf Spring U Bolt with Nut Zinc Plating for Truck Spare Parts Rear

Описание

What Are Leaf Spring U Bolts?

Leaf spring U bolts are heavy-duty, U shaped fasteners specifically engineered to secure leaf spring assemblies to axles in vehicles and machinery. Their unique design clamps the spring pack while withstanding dynamic loads, vibrations, and shock impacts.

Leaf Spring U Bolt: Specifications

1. Material

• Carbon Steel (Grade 8.8): Cost-effective for standard vehicles

• Alloy Steel (4140): Heat-treated for heavy trucks (up to 180,000 PSI tensile)

• Stainless Steel (316): Corrosion-resistant for marine/off-road use

2. Surface Treatment

• Hot-Dip Galvanized: 85-micron coating for salt/snow environments

• Dacromet® Coating: Zinc-flake technology (1,000+ hrs salt spray)

• Black Oxide: OEM aesthetic + mild corrosion resistance

3. Common Specifications

• Diameter: 10mm–24mm (M10–M24)

• Inside Width: Matches axle tube diameter (50mm–150mm typical)

• Thread Length: 2.5× bolt diameter minimum

• Standards: SAE J429, DIN 3570

4. Applications

• Commercial Trucks: Semi-trailer suspension systems

• Agriculture: Tractor and harvester axle mounting

• Military: Armored vehicle spring retention

• Railway: Bogie spring block fastening

Excellent Case: Mining Dump Truck Suspension Upgrade

Challenge:
A mining operator experienced U bolt failures every 3 months on 100-ton dump trucks due to:

• Corrosion from acidic slurry

• Fatigue from constant 5G shock loads

Solution:

• Installed Dacromet-coated 4140 alloy U bolts (M22):

  • Corrosion Protection: 5× longer life vs. galvanized bolts

  • Fatigue Resistance: Shot-peened threads survived 1M+ cycles

  • Torque Retention: Serrated flange nuts prevented loosening

Results:

• Extended service interval from 3 to 18 months

• Reduced unplanned downtime by 67%

• Passed ISO 6336 fatigue testing

Key Advantages

✔ Vibration-Proof – Locking nut options eliminate retorquing
✔ Custom Geometry – Offset bends for clearance-critical designs
✔ Safety Compliance – Meets DOT/FMCSA roadside inspection standards