M6 M8 M10 M12 U Bolt With 2 Hex Nuts Zinc-Plated U-Bolts Clamp Pipe Tube Metric

The three numbers represent Thread Diameter × Inside Width × Leg Length, all in millimetres. So M8*42*75 means an M8 threaded rod, an inside width of 42 mm (the gap the pipe sits in), and a leg length of 75 mm (the straight section below the bend on each side). Match the inside width to your pipe or tube outer diameter.

The inside width of the U-bolt should match or be very slightly larger than the outer diameter of your pipe or tube. For example, a U-bolt with a 42 mm inside width is designed for pipe with an outer diameter of approximately 42 mm. If your pipe OD falls between two sizes, choose the next size up to ensure the bolt seats properly without forcing.

Yes — every U-bolt in this listing ships with two matching hex nuts. The nuts are standard metric coarse-pitch, compatible with the U-bolt thread. Grade details are not specified on the listing; if your application has specific load or torque requirements, contact us to confirm suitability before ordering.

The zinc electroplated finish provides corrosion resistance suitable for dry indoor environments and sheltered outdoor locations where the fastener is not directly exposed to standing water, salt spray, or prolonged moisture. For fully exposed outdoor, marine, or high-humidity applications, a stainless steel U-bolt would be a more appropriate choice.

Thread size selection depends on the load the clamp must carry and the mounting surface. M6 is suitable for light-duty clamping of small-diameter pipe or conduit. M8 and M10 cover the majority of general workshop and plumbing applications. M12 is appropriate for heavier pipe, structural tube, or applications where higher clamping torque is needed. When in doubt, size up — a larger thread diameter adds clamping strength without significant cost increase at these sizes.

The leg length is the straight threaded section on each side of the U-bolt that passes through the mounting plate or bracket. You need enough leg length to pass through your mounting surface and still have sufficient thread engagement for both hex nuts — typically at least 10–15 mm of thread beyond the mounting surface. Measure your bracket thickness and add this engagement allowance when selecting a leg length.

These U-bolts are designed for round pipe and tube profiles. The curved bend is sized to match a specific round outer diameter. Using them on square or rectangular tube is not recommended, as the contact geometry will be incorrect and clamping force will be uneven, potentially damaging the tube or allowing movement under load.