Marine Grade Round Bend U-Bolts — A2 & A4 Stainless Steel, M6 to M20

Match the thread diameter (M6, M8, M10, M12, M16, or M20) to your existing nut or tapped hole. For length, measure the pipe or bar diameter you are clamping, then add twice the thread engagement depth you need. As a general rule, the inside width of the U-bolt should match the outer diameter of the pipe or round bar. For example, an M8 x 38mm (≈1.5") U-bolt typically suits a pipe with roughly 25–32 mm OD. When in doubt, size up one step.

A2 (304 grade) stainless steel offers good general corrosion resistance and is suitable for most indoor and sheltered outdoor applications. A4 (316 grade) adds molybdenum, giving it significantly better resistance to chlorides and salt water, making it the preferred choice for marine, coastal, and chemical environments.

Yes. Both grades are corrosion-resistant. For freshwater outdoor use, A2 is generally sufficient. For saltwater, coastal, or marine applications, A4 (316 grade) is strongly recommended due to its superior chloride resistance. Neither grade will rust under normal conditions, but A4 provides an extra margin of protection in aggressive environments.

These U-bolts use standard ISO metric coarse threads (DIN 3570 / DIN 255 style). They are compatible with standard metric hex nuts and washers of the corresponding size (M6, M8, M10, M12, M16, M20). For best results in corrosive environments, use matching stainless steel nuts and washers of the same grade (A2 with A2, A4 with A4) to avoid galvanic incompatibility.

Load capacity depends on thread diameter, material grade, and installation torque. As a general reference, A2-70 and A4-70 stainless fasteners are rated to a minimum tensile strength of 700 MPa. Larger diameters (M12, M16, M20) can typically handle significantly higher loads than smaller ones (M6, M8). For structural or safety-critical applications, always consult an engineer and refer to the relevant load tables for the specific size and grade.

Please check the variant listing or contact us to confirm. Typically, round bend U-bolts of this type are supplied as the U-bolt body only. Matching stainless steel nuts and washers are available separately. We recommend using the same grade (A2 or A4) for all fastener components in the assembly.

Match the inside width of the U-bolt to the outer diameter of your pipe. For example, an M8 x 25mm (≈1") U-bolt typically suits a pipe with roughly 15–20 mm OD, while an M10 x 60mm (≈2.4") suits pipes around 40–50 mm OD. These are general estimates — if you are unsure, contact us with your pipe OD and we will help you select the correct size.

These stainless steel round bend U-bolts are generally suitable for exhaust bracket mounting, roll-cage tube clamping, and similar automotive fabrication uses where metric threads are required. For high-heat exhaust applications, verify that the operating temperature does not exceed the limits of 304 or 316 stainless steel (typically up to around 870°C / 1600°F for intermittent exposure, though sustained high heat may affect strength). Contact us if you need further guidance.