Trailer U-Bolt Bracket 70x140 mm (55 mm internal width)

This 70x140 mm U-bolt is a key fastener in assembling and maintaining boat trailers. It allows you to securely clamp various components to the trailer’s frame – for example, keel roller brackets, bunk support brackets, fenders, or even axles to leaf springs. The U-bolt is made of strong steel with a hot-dip galvanized coating, which protects it from rust and ensures a long service life even when frequently exposed to water. The outer width of the U-bolt is 70 mm, and the inner distance between the threaded legs is about 55 mm – this makes it suitable for wrapping around standard 50x50 mm square tubes (a common size for small and mid-size trailer frames) or equivalently around round pipes of about 50 mm diameter. The leg length of 140 mm provides sufficient height to encompass the frame and the component you are mounting, while leaving room to fasten the nuts underneath.

The U-bolt comes with threads cut on the ends of both legs and typically includes the necessary nuts (and sometimes washers) for tightening. When installing, ensure that the surfaces being clamped by the U-bolt are flush and properly aligned – for better grip and to avoid slippage, you can use flat washers and lock nuts or nylon-insert nuts. Once tightened down firmly, the U-bolt will hold the component in a fixed position and resist vibrations during transport.

Applications and tips:

• Mounting keel rollers and supports: This U-bolt is ideal for attaching keel roller brackets or bunk support brackets to the trailer frame – for instance, if adding an extra roller or replacing an old U-bolt, the 70x140 size will fit in most such setups
• Securing fender brackets and accessories: Use 70x140 mm U-bolts to fix fender mounts, step pads or even the winch post onto a square drawbar (if the design permits) – its size is versatile for many add-ons on the trailer
• Clamping axle to springs: Some trailer axle-to-spring connections use U-bolts – check your dimensions, and if your setup involves ~50 mm diameter axle or mounting plate, this U-bolt can serve as a spare or replacement part
• Load durability: The galvanized steel U-bolt can handle significant tensile loads – however, it’s important to always use all intended U-bolts (e.g., typically 2 or 4 per axle) and tighten them evenly to distribute the stress
• Maintenance: Periodically inspect the U-bolts on your trailer – vibrations over time can loosen the nuts. Re-tighten if necessary and watch for any signs of rust. Despite galvanization, if the coating gets chipped (by scratches or impacts), corrosion can start – if you see reddish areas, consider replacing the U-bolt or applying additional anti-corrosion spray for protection