2x TROJAN M12 Square Trailer U Bolts 51x85mm Galvanised for 50mm Round Axle (SKU: 271050)

These TROJAN M12 Square U Bolts (51x85mm) are a compact and durable fastening solution for 50mm round trailer axles. Built to last, they feature a galvanised finish that offers excellent protection against rust and wear, even in demanding outdoor and coastal environments.

Key Features:

• Internal Width: 51mm
• Arm Length: 85mm – perfect for low-profile applications
• Thread Length: 40mm for secure fitment
• Diameter: M12 (12mm)
• Finish: Galvanised steel – highly corrosion resistant
• Fits: 50mm round trailer axles

These U bolts are ideal for applications where space is limited, such as in compact trailers or where axle mounting clearance is tight. The galvanised steel ensures longevity and toughness under vibration, road grime, and moisture exposure.

Common Uses:

• Utility trailers with compact suspension systems
• Boat trailers in marine environments
• Off-road trailers requiring durable axle mounts

Each set comes with nuts and washers for easy, secure installation, allowing you to get back on the road or back on the water with confidence.

Frequently Asked Questions

Evaluation & Recommendation

This U bolt set is great for those looking for a short-arm solution in trailer setups with limited space. The 85mm arm length makes it perfect for compact builds or retrofits where standard-length bolts won’t fit. It meets all strength and durability expectations for trailer axle clamping.

Recommended For:

• DIY trailer builders with compact designs
• Users upgrading or maintaining existing U bolt assemblies on 50mm round axles
• Environments with high exposure to moisture, where galvanised coating is essential

If you require extra clearance or have a different axle profile, reach out — we’ll help match you with the right size and type for your project.

Installation Tips:

• Always check for proper alignment before tightening
• Use nyloc nuts (included) to prevent loosening from vibration
• Tighten evenly on both sides for balanced pressure