A trailer U-bolt kit is the fastener set that anchors a leaf spring assembly to the axle. It usually pairs the U-bolt with the correct grade of nuts and washers — a matched set that takes the guesswork out of a suspension repair. U-bolts are safety-critical: every bump and loaded mile transmits force through them, and a failure means loss of vehicle control. Getting the bend type, diameter, and leg length right matters more than almost anything else on a trailer.
Jrs Farm Parts is a U-bolt manufacturer and exporter based in Ludhiana, India (ISO 9001:2015). We are not a US manufacturer — we produce high-tensile U-bolts in our Indian facility and export directly to US distributors, farm supply stores, and fleet maintenance operations.
Round bend vs square bend vs V-shape
| Bend type | Axle it fits | Typical use |
|---|---|---|
| Round bend | Tubular (round) axles | Utility, boat, and agricultural trailers |
| Square bend | Square / rectangular axle beams | Heavy trailers and equipment haulers |
| V-shape | Specialized mounting profiles | Suspension and implement applications |
The bend profile must match the axle cross-section: a round bend wraps the tube with even clamping pressure; a square bend mates flat against a square beam. A mismatched bend can loosen under vibration and damage the axle.
How to size a U-bolt kit
- Axle diameter or width — measure the axle cross-section at the spring seat (this sets the bend size)
- Spring seat depth — the vertical space the U-bolt must bridge
- Bolt diameter — match the existing hardware and torque spec (commonly 1/2", 9/16", 5/8" in trailer service)
- Thread length & finish — enough thread for the nuts plus a corrosion-resistant finish (zinc plated standard)
- Nuts and washers — kits include grade-matched hardware; torque to the suspension manufacturer’s spec
No two trailers are identical — confirm dimensions with our export team before ordering so the kit matches your axle and spring seat exactly.
U-bolt quality that matters
At Jrs Farm Parts, U-bolts are manufactured from high-tensile alloy steel grades (16MnCr5 / 42CrMo4), with rolled threads rather than cut threads for superior fatigue resistance, and zinc-plated (clear or yellow) or powder-coated finishes. Every batch is dimensionally verified and tensile-tested under our ISO 9001:2015 quality system.
Wholesale for distributors and dealers
We supply U-bolt kits in bulk to US trailer parts distributors, farm supply stores, and fleet maintenance operations — factory-direct pricing, no middlemen. Production runs ~40 days plus ocean freight; documentation (COO, commercial invoice, packing list) included.
Request a quote: Request a Quote or email jrsfarmparts@gmail.com.
Frequently Asked Questions (FAQ)
What is included in a trailer U-bolt kit?
Typically the U-bolt(s) plus matching nuts and washers, sized for a specific axle and spring seat configuration. Confirm the exact contents with our export team for your application.
How do I know if I need round bend or square bend U-bolts?
Round bend fits tubular (round) axles; square bend fits square or rectangular axle beams. Measure the axle cross-section at the spring seat to decide.
Do you sell U-bolt kits wholesale to the USA?
Yes — we are a direct manufacturer exporting to US distributors and dealers with bulk pricing and full export documentation.
Are Jrs Farm Parts U-bolts made in the USA?
No. We manufacture in Ludhiana, India (ISO 9001:2015) and export to the USA and 60+ countries.
Shop U-bolts: U-Bolts (Round Bend), U-Bolts (Square), U-Bolt (V Shape) · Trailer U-Bolts category · Trailer Parts & Accessories. See also the Trailer Coupler Guide and Jockey Wheel & Parking Jack Guide.
See also our excavator bucket teeth guide and our import pages for the UK and Italy.
