M6 M8 M10 M12 U Bolt Plates & Nuts Standard U-Bolts Stainless Steel 304 Trailer

Match the inside width (the third number in the size code, e.g., 50 mm in "M8 x 30 x 50mm") to the outer diameter of your pipe or axle. The inside width should equal or very slightly exceed the OD of the pipe so the U-bolt seats flush against both sides. The shank length (second number) determines how much thread protrudes through the plate for nut engagement — allow at least 1.5× the thread diameter of exposed thread.

Working load depends on thread diameter, material grade, and installation torque. Grade 304 stainless steel has a tensile strength of approximately 515 MPa. For safety-critical applications such as trailer axle retention, consult an engineer and apply an appropriate safety factor. Always torque nuts to the manufacturer's specification for the thread size.

Grade 304 stainless steel offers good resistance to atmospheric corrosion and fresh water. It performs well in mild marine environments. For continuous saltwater immersion or highly chlorinated environments, Grade 316 stainless is generally recommended. These U-bolts are well-suited for trailer use near coastal areas where exposure is intermittent.

Yes. The flat bearing plates included with each set work with both round pipe and flat/square profiles. For round pipe, the plate bears against the pipe tangentially; for square tube, it seats flat. Ensure the inside width of the U-bolt spans the full width of the square tube you are clamping.

Yes. Each set is supplied as a matched assembly — the hex nuts are threaded to the same metric pitch as the U-bolt body. No thread chasing or re-tapping is required. If you need additional nuts for a double-nut locking arrangement, specify the thread diameter (M6, M8, M10, or M12) when sourcing replacements.

A standard single-axle trailer leaf-spring setup uses two U-bolts per spring perch — one on each side of the center bolt. That means four U-bolts total for a single axle. Select the 2 pcs pack to cover one spring perch, or order two 2 pcs packs to cover a full axle in one order.

You need a wrench or socket set matching the hex nut size for your thread diameter (M6 = 10 mm, M8 = 13 mm, M10 = 17 mm, M12 = 19 mm are typical across standard metric hex nuts), and a torque wrench for safety-critical applications. No special tools are required — these install with standard metric hand tools.