39mm Round Galvanised U-Bolt Kits

SKU: UK39R Categories: ,
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Galvanised U-Bolt Kits are suitable for:

 Boat Trailers
Caravans & Campers
Horse Floats
General Purpose Trailers

U-Bolts are measured on their internal dimensions to ensure proper fit and alignment with the equipment.

39mm Round Galvanised U-Bolt Kits


Couplemate™ U-Bolt Kits are strength-tested and galvanised for longevity.

U-bolts play a vital role in keeping your entire caravan secure. They connect the axle to the springs, and in turn, connect everything to the trailer chassis. Therein, it's very important that you buy the right U-Bolts for the job.

1/2" Galvanised U-Bolts are suitable for 45mm springs with a weight capacity of up to 1500kg for single axle and 3000kg for tandem trailers.

If you have an Off-Road Camper, Rocker-Roller Springs, or an ATM that exceeds these weight capacities, Couplemate™ recommends opting for a Heavy-Duty U-Bolt Kit.

Product Specifications


  • Materials: Steel, Zinc
  • Coating: Traditional Galvanised
  • Diameter: 1/2" (12.70mm)
  • Torque Setting: 60Nm
  • Thread Length: 50mm
  • Capacity: 1500kg (per kit)

U-Bolt Kit Contents

Couplemate™ U-Bolt Kits are sold to suit a single-axle suspension. If you have tandem suspension, you will require two kits.

  • 4 x U-Bolts
  • 8 x Zinc Washers
  • 8 x Nyloc Nuts
  • 2 x Fish Plates
  • 2 x Axle Pads

How to Measure U-Bolt Length


How do you know what U-Bolt length you need? Here is the calculation:

Minimum U-Bolt Length = Axle Thickness + Axle Pad Thickness + Spring Width + Fish Plate Thickness + Nuts & Washer Thickness

Couplemate™ U-Bolt kit contents have the following set measurements:

  • Axle Pad = 10mm
  • Fish Plate = 10mm
  • Nut & Washers = 27mm

For example, if you have a 50mm Axle with 7 Leaf Springs (56mm), your calculation would be:
50mm + 10mm + 56mm + 10mm + 27mm = 153mm

Additional information

Weight4 kg
Dimensions20 × 10 × 5 cm
U-Bolt Length

100mm, 112mm, 125mm, 137mm, 150mm, 162mm, 175mm, 200mm

Replacement Jockey Wheels

Jockey Wheel Replacement Wheels and Tyres to suit 150mm, 200mm, and 350mm

Easy Axle Jack.

Easy Jack CM070

Easily lift your trailer or caravan by the axle without a mechanical jack.

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