800 kg Trailer Coupler – Round Tube Hitch (Ø60 mm / Ø70 mm, Galvanized)

This 800 kg trailer coupler for round tongues fills the need for trailers whose frames are cylindrical rather than square. Often, smaller boat trailers or specialized trailers use round tubing for their frame, and this model is tailored for that. The curved inner shape of the coupler ensures a snug wrap-around fit on the round tube, with no gaps. It comes in two standard diameters: Ø60 mm and Ø70 mm, covering most small to mid-size trailers with a round drawbar or chassis member.

Construction and mounting: The coupler is made of robust steel, shaped internally to cradle a cylindrical tube. During installation, the two halves of the coupler “clamshell” around the tube and are secured with bolts on either side. The Ø60 mm and Ø70 mm versions have different curvatures inside to match their respective diameters. Typically, installation uses two bolts passing through holes in the coupler that align with drilled holes in the tube (if the tube isn’t pre-drilled, holes need to be made). The bolts are tightened firmly, clamping the coupler to the tube and providing stability.

At the front, the coupler features a 50 mm ball hitch mechanism – the same standard interface as square couplers. The locking lever works identically: it allows easy hitching and unhitching of the trailer but keeps a firm hold on the ball during motion. There is also a safety hole where you can insert a locking pin or padlock to prevent accidental uncoupling or theft.

Advantages of this model:

• Its specialization for round tongues makes the installation much more reliable compared to trying to improvise a square coupler onto a round tube. Here, the contact surface is optimal and the clamping force is distributed evenly around the tube.
• The galvanized finish ensures that even if you use the trailer in wet conditions – e.g., submerging it in a lake/ocean as a boat trailer – the coupler will resist corrosion. This extends its lifespan and keeps it looking and functioning well.
• Lightweight and compact design: Couplers in the 800 kg class tend to be lighter and smaller than heavier models, which is a plus for small trailers as they don’t add unnecessary weight at the front and are easy to handle.
• Compatibility: This coupler is compatible with all vehicles equipped with a European tow ball (50mm). It can be used on passenger cars, SUVs, or even small tractors/ATVs, as long as they have a standard hitch ball.

Applications:
Designed mainly for boat trailers and trailers with specialty construction:

• Boat trailers with tube frames: For example, trailers for motorboats, fishing boats, or sailboats, where the structure often uses round tubing to reduce weight and improve torsional flexibility.
• Jet-ski trailers: Many of these also have round frame profiles and are light – this coupler suits them perfectly.
• Specialty trailers: Flatbed ATV trailers or custom builds that use tubular steel.
• It can also be used for older style or home-built trailers that have a round drawbar.

Tip for installation: Check the wall thickness of the tube – if it’s relatively thin, ensure that tightening the bolts won’t deform the tube. If necessary, use internal sleeves or inserts in the tube at the clamping area to reinforce it. After installation, as with all couplers, test for proper locking on a hitch ball and keep the moving parts lubricated for smooth operation.

With this round-tongue coupler, you’ll be using the right tool for the job – your trailer will be secured exactly as the frame’s design intended. This brings peace of mind when towing, knowing that the connection is solid, reliable, and suited to the conditions in which you’ll use the trailer.