Product Overview This product is a hot-dip galvanized carbon steel U-bolt pipe clamp (also known as a U-bolt, U-clamp, saddle bolt, or U-pipe clamp), designed to secure pipes, tubes, conduits, and cables to structural supports, walls, ceilings, and racks. The U-bolt features a square bend configuration with metric threads (M8 standard, M6–M16 available) on both legs, and is supplied complete with two hex nuts for immediate installation. Manufactured from Q235 carbon steel and finished with hot-dip galvanizing (HDG) to ISO 1461 / ASTM A153, this U-bolt provides superior corrosion resistance for outdoor, coastal, and humid environments — making it particularly suited for the Middle East's salt-laden air and extreme climatic conditions. The U-bolt conforms to DIN 3570, JB/ZQ 4321, and related international standards, and is available in sizes covering DN15 to DN500 (½" to 20") pipe diameters. The square bend design provides a flat bearing surface against mounting plates and strut channels, preventing rotation and ensuring stable, vibration-resistant pipe support. This is the preferred configuration for pipe rack installations, HVAC ductwork, fire-fighting pipework, and cable tray systems in industrial and commercial construction. Product Type & Design Feature Description Product Type U-Bolt / U-Pipe Clamp / Saddle Bolt / U-Screw Bend Type Square bend (also available: round bend, long leg) Thread Configuration Metric threads on both legs (right-hand) Thread Tolerance 6g (metric) Standard Thread Size M8 × 1.25 (standard); M6, M10, M12, M16 available Nut Configuration Two hex nuts supplied per U-bolt (standard) Product Grade A / B (per DIN 3570) The square bend creates a flat contact area on the mounting surface, distributing clamping force evenly and preventing the U-bolt from rotating during tightening. The threaded legs allow the clamp to be tightened from the underside of the support structure, accommodating a wide range of pipe diameters and insulation thicknesses. For larger diameters (DN 50 and above), four nuts are typically used — two above and two below the support plate — to provide additional security and adjustment. Material & Grade Parameter Details Material Q235 carbon steel (standard); Q345B, 45#, alloy steel available Strength Grade 4.8 (standard); 8.8 available on request Chemical Composition (Q235) C ≤ 0.22%, Mn ≤ 1.4%, Si ≤ 0.35%, S ≤ 0.050%, P ≤ 0.045% Tensile Strength ≥ 400 MPa (Grade 4.8) Yield Strength ≥ 320 MPa (Grade 4.8) Elongation ≥ 22% Density 7.85 g/cm³ Q235 carbon steel is the standard material for U-bolt pipe clamps, offering an excellent balance of strength, ductility, and cost-effectiveness. For higher load requirements, Grade 8.8 alloy steel (35CrMo, 40Cr) is available, achieving a minimum tensile strength of 800 MPa. Stainless steel (SS304 / SS316) options are also available for highly corrosive environments. Surface Finish — Hot-Dip Galvanizing (HDG) Parameter Specification Standard ISO 1461 / ASTM A153 / GB/T 13912 Coating Thickness 45–85 μm (typically ≥ 50 μm for M8–M16) Coating Weight ≥ 350 g/m² Salt Spray Resistance 500–1,500+ hours (to red rust) Maximum Service Temperature 200–250°C (continuous) Appearance Bright silver-gray, uniform matte finish Corrosion Mechanism Barrier + sacrificial (cathodic) protection Hot-dip galvanizing provides sacrificial (cathodic) protection to the underlying carbon steel. The zinc coating corrodes preferentially, protecting the steel substrate from rust even if the coating is scratched or damaged. The metallurgically bonded zinc-iron alloy layer formed during the hot-dip process ensures excellent adhesion and long-term durability. Performance comparison: Finish Coating Thickness Salt Spray Resistance Recommended Environment Hot-Dip Galvanized (HDG) 45–85 μm 500–1,500+ hours Outdoor, coastal, marine, industrial Zinc Plated (Electro) 8–12 μm 72–144 hours Indoor, protected environments Dacromet 5–12 μm 600–1,500+ hours Coastal, offshore, high-corrosion Hot-dip galvanizing is strongly recommended for GCC projects due to the region's high humidity, salt-laden coastal air, and extreme temperature fluctuations. For oil & gas, petrochemical, and offshore applications, HDG U-bolts to ASTM A153 provide the required corrosion resistance and service life. Standards & Specifications Parameter Details Standards DIN 3570 / JB/ZQ 4321-1997 / JB/ZQ 4321-2006 / GB/T 2314 Thread Sizes M6, M8, M10, M12, M16, M20, M24 Pipe Diameter Range DN15 – DN500 (½" – 20") Inner Width (a) 30 mm – 530 mm (DN 20 – DN 500) Thread Length (b) 40 mm – 70 mm (varies by size) Bend Type Square / Round / Long Leg Material Q235 / Q345B / 45# / 35CrMo / SS304 / SS316 Surface Finish HDG / Zinc Plated / Dacromet / Plain (for SS) Nut Supply 2 hex nuts per U-bolt (standard); 4 nuts for DN 50+ DIN 3570 is the primary international standard for U-bolts, specifying Type A (round bar) and Type B (flat bar) configurations. The standard covers inner width from 30 mm to 530 mm (DN 20 – DN 500), with thread sizes M10, M12, M16, M20, and M24. JB/ZQ 4321-1997 / 2006 is the Chinese national standard for U-bolts, technically equivalent to DIN 3570, covering sizes from M6 to M48. Key Dimensions (Reference — Square Bend, M8) Pipe Size (DN) Inner Width (a) mm Thread (d) Thread Length (b) mm Leg Length (L) mm DN15 (½") 21.3 M8 40 65 DN20 (¾") 26.9 M8 40 70 DN25 (1") 33.7 M8 40 75 DN32 (1¼") 42.4 M8 40 85 DN40 (1½") 48.3 M8 40 90 DN50 (2") 60.3 M8 40 100 DN65 (2½") 76.1 M10 50 115 DN80 (3") 88.9 M10 50 125 DN100 (4") 114.3 M12 60 150 All dimensions are in accordance with DIN 3570 / JB/ZQ 4321 standards. Custom sizes available on request. Bar diameter reference: The "6, 8, 10, 12" designation commonly used in the industry refers to the bar (wire) diameter of the U-bolt, not the thread size. For M8 U-bolts, the bar diameter is typically 8 mm. For larger pipe diameters, the bar diameter increases proportionally (M10 = 10 mm, M12 = 12 mm, M16 = 16 mm). Mechanical Properties (Reference — Q235 / Grade 4.8) Property Value Tensile Strength ≥ 400 MPa Yield Strength ≥ 320 MPa Elongation ≥ 22% Hardness ≤ 255 HV Service Temperature Range −40°C to +120°C (HDG) For Grade 8.8 U-bolts (alloy steel 35CrMo / 40Cr), tensile strength reaches ≥ 800 MPa with yield strength of ≥ 640 MPa, suitable for heavy-load pipe support and high-vibration applications. Applications Hot-dip galvanized U-bolt pipe clamps are widely used across industries: Plumbing & Sanitary — Domestic water supply, drainage, and sewerage pipework HVAC & Chilled Water — Refrigerant lines, condensate drains, ductwork supports Fire-Fighting Systems — Sprinkler pipework, fire mains, hydrant piping Oil & Gas — Process piping on racks and sleepers, pipeline supports, wellhead connections Petrochemical Plants — Chemical process piping, steam lines, utility piping Power Plants & Desalination — Cooling water lines, steam piping, brine discharge systems Cable Management — Electrical conduit, cable tray, and ducting supports Solar & Renewable Energy — Solar mounting rail pipe fixation, battery room piping Water Treatment — Filtration, pumping, and distribution pipework Marine & Offshore — Deck piping, ballast systems, seawater cooling lines Regional insight: In the Middle East, HDG U-bolt pipe clamps are routinely specified for pipe rack installations in oil & gas facilities, HVAC systems in high-rise buildings, and fire-fighting pipework across the UAE, Saudi Arabia, Qatar, and Oman. The hot-dip galvanized finish ensures long-term performance in the region's harsh coastal and desert environments. GCC market context: The Middle East pipe clamp market is valued at approximately USD 950 million, driven by the region's massive construction and infrastructure programs. HDG U-bolts are the standard choice for outdoor and humid environments where zinc-plated products would fail within 1–2 years. Installation Guidelines Verify pipe outside diameter: U-bolt size is selected by the pipe outside diameter (OD), not the nominal pipe size. Confirm OD against the U-bolt inner width before ordering. Thread engagement: For standard installation, two nuts per leg are recommended — one above and one below the support plate. For larger diameters (DN 50+), four nuts per leg may be required for additional security. Mounting plate thickness: The support plate or strut channel should be at least 6–10 mm thick for M8 U-bolts. Thicker plates require longer leg lengths. Torque specification: For M8 Grade 4.8 U-bolts, recommended tightening torque is 15–20 N·m. For M10, 30–35 N·m; for M12, 50–60 N·m. Do not exceed 80% of proof load. Insulation consideration: When clamping insulated pipes, specify a U-bolt with a larger inner width to accommodate the insulation thickness, or use a rubber-lined U-bolt clamp to prevent insulation damage. Vibration resistance: For pipework subject to vibration (compressors, pumps, engines), use spring washers or nylon-insert lock nuts in addition to standard hex nuts. Thermal expansion: For hot water or steam lines, tighten only the bottom nut (guide support) to allow axial pipe movement. For anchor points, tighten both nuts. Quality Assurance All products are manufactured under strict quality control procedures in accordance with DIN 3570, JB/ZQ 4321, ISO 1461, and ASTM A153 standards. Quality control steps performed on each production batch: Chemical composition verification of raw material (Q235 / alloy steel) Tensile and yield strength testing per ISO 898-1 Thread gauge inspection (go/no-go gauges) for 6g tolerance Coating thickness measurement (magnetic gauge) per ISO 1461 Coating adhesion test (knife test / bend test) Visual inspection for surface defects, cracks, and coating uniformity Documentation available on request: EN 10204 3.1 Material Test Certificate EN 10204 3.2 (for critical applications) Coating thickness certificate (HDG) Dimensional inspection report Third-party inspection reports (SGS, BV, CTI) Packaging & Customization Export Packing: Wooden case / steel pallet / bundle with strapping Domestic Packing: Corrugated carton / plastic bag / bulk Nut Supply: Two hex nuts per U-bolt (standard); four nuts for DN 50+ Washer Supply: Flat washers and spring washers available on request OEM/ODM: Available — custom sizes, bend types (square/round/long leg), materials (SS304, SS316, alloy steel), thread types (metric/UNC/BSW), and surface finishes can be produced according to drawings or samples MOQ: Negotiable Ordering Information To place an order or request a quotation, please specify: Product type — U-bolt pipe clamp (square bend / round bend / long leg) Standard — DIN 3570 / JB/ZQ 4321 / GB/T 2314 / to drawing Material — Q235 carbon steel / Q345B / 45# / 35CrMo / SS304 / SS316 Strength grade — 4.8 / 8.8 Pipe outside diameter (OD) — e.g., 60.3 mm (DN50 / 2") Thread size and pitch — e.g., M8 × 1.25 Inner width (a) — Specify if non-standard Thread length (b) — Specify if non-standard Leg length (L) — Specify if non-standard Surface finish — HDG (ISO 1461 / ASTM A153) / Zinc plated / Dacromet / Plain Nut and washer supply — Specify quantity and type Quantity — With any tolerance for over/under shipment Certification — EN 10204 3.1 MTC / SASO (for Saudi Arabia) / EAC (for Kazakhstan) Special requirements — Rubber liner, insulation block, marking, packaging