U-Bolts
U-bolts are curved fasteners designed to secure pipes, tubes, cables, and other cylindrical or tubular components to supporting structures. Their U-shaped body wraps around the component, while the two threaded legs pass through a bracket, plate, channel, or other support and are tightened with nuts. This arrangement provides stable clamping without requiring a hole to be drilled through the component being secured, making U-bolts a practical choice for piping, mechanical equipment, structural assemblies, and utility installations.
Our U-bolts are available in both metric and inch sizes to meet different dimensional requirements. Metric U-bolts can be manufactured to DIN 3570, while inch-series U-bolts can be supplied according to ASME B18.31.5. Different diameters, leg lengths, inside widths, threaded lengths, and bend dimensions are available according to the applicable standard or customer requirements. Carbon steel, alloy steel, and stainless steel options are available, with finishes such as plain, zinc plated, and hot-dip galvanized to suit different installation and service environments.
Specification:
| Item | Metric U-Bolts | Inch U-Bolts |
|---|---|---|
| Size Range | M6-M24 | 1/4"-1" |
| Dimension Standard | DIN 3570 | ASME B 18.31.5 |
| Thread | ISO Metric Coarse,Fine Thread | UNC,UNF |
| Thread Standard | ISO 261, ISO 965 | ASME B1.1 |
| Thread Class | 6g | 2A |
| Material | Cabon Steel,Alloy Steel,Stainless Steel,Aluminum,Brass | Cabon Steel,Alloy Steel,Stainless Steel,Aluminum,Brass |
| Steel Property Class | ISO898-1,Class4.8,6.8,8.8,10.9,12.9 | SAE Grade2,5,8 ASME A307,A193 B7 |
| Stainless Steel Class | A2-70,A2-80,A4-70,A4-80 | F593C, F593D, F593G,F593H |
| Surface Treatment | Black Oxidation, Zinc Plated, HDG, Dacromet, Bright Finish,Passivation | |
| Inspection | Dimension,Thread,Mechanical Proeprty,Coating | |
Dimension Standard:
U-bolt dimensions are selected according to the diameter of the fastener, inside width of the U-shaped body, leg length, threaded length, and bend configuration. The inside width and leg length are particularly important when the U-bolt needs to fit around a pipe, tube, or other component and connect it to a specific support. Metric and inch-series U-bolts follow different dimensional systems, so the applicable standard should be confirmed when selecting a size.
ASME B 18.31.5 U-Bolts
ASME B18.31.5 covers inch-series bent bolts, including U-bolts, with dimensions specified in inches. Depending on the U-bolt configuration, dimensions include the nominal diameter, inside width, leg length, threaded length, and bend-related dimensions. This standard is suitable for applications using inch-based piping, equipment, and structural components.
DIN 3570 U-Bolts
DIN 3570 specifies metric U-bolts with dimensions expressed in millimeters. The standard covers the main dimensions of the U-shaped body and threaded legs, making it suitable for selecting U-bolts according to the outside diameter and mounting requirements of the component. DIN 3570 U-bolts are commonly selected for metric piping, tubing, and equipment support applications.
Mechanical Proeprty:
The mechanical properties of U-bolts depend on the material grade and the applicable fastener specification. Different applications may require requirements for tensile strength, yield or proof strength, hardness, and other mechanical properties. Our U-bolts can be manufactured to commonly specified metric and inch-series material standards, with the applicable grade selected according to the required strength, temperature, corrosion resistance, and service conditions.
ISO 898-1 Carbon Steel U-Bolts
ISO 898-1 specifies mechanical and physical properties for carbon steel and alloy steel fasteners in metric sizes. U-bolts manufactured to applicable property classes can be selected where a defined strength level is required for general mechanical and structural fastening applications.
SAE J429 U-Bolts
SAE J429 defines mechanical and material requirements for inch-series carbon and alloy steel fasteners. Grades such as Grade 5 and Grade 8 provide different strength levels and are commonly selected for mechanical and structural applications where inch-series fastener requirements apply.
ASTM A193 U-Bolts
B7 U-bolts are suitable where higher mechanical strength and resistance to demanding service conditions are required. ASTM A193 Grade B8 and B8M cover austenitic stainless steel fasteners. B8 is based on Type 304 stainless steel, while B8M is based on Type 316 stainless steel. These grades combine mechanical strength with corrosion resistance and are selected according to the environment and temperature requirements of the application.
ISO 3506-1 Stainless Steel U-Bolts
For DIN 3570 U-bolts, the dimensions and configuration are specified by DIN 3570, while stainless steel material and mechanical properties can be selected according to applicable requirements of ISO 3506-1. 304 U-bolts (A2) are commonly used for general applications requiring good corrosion resistance, while 316 U-bolts (A4) contain molybdenum and provide better resistance to chlorides and more aggressive environments, making them suitable for marine, coastal, chemical, and other demanding applications.
ASTM F593 Stainless Steel U-Bolts
For stainless steel U-bolts, the dimensional and configuration requirements can be based on ASME B18.31.5, while applicable ASTM F593 material and mechanical requirements can be specified according to the required stainless steel grade and strength condition.
Related Bolt Products
U-bolts are particularly useful for securing pipes, tubes, and other components by wrapping around their outside surface. When a different fastening arrangement is required, hex bolts can be used for general through-hole connections, while flange bolts provide a larger bearing surface beneath the head. For heavier structural and mechanical connections, heavy hex bolts offer a larger head and bearing surface, while stud bolts are commonly used for flanged assemblies and applications where repeated installation and removal may be required.