Bolts
U-Bolt
Accurate Fastners manufactures and supplies stainless steel U-Bolts in grades SS 202, SS 304, and SS 316, covering metric diameters from M3 to M24. With 21 years of fastener manufacturing experience, each U-Bolt undergoes quality checks during procurement and at delivery.
- Standard
- —
- Grades
- 202 / 304 / 316
- Size
- M3 – M24
- Length
- On enquiry
Overview
What is the U-Bolt?
A U-Bolt is a bent fastener shaped like the letter 'U', with both straight legs threaded to accept nuts. Unlike a conventional bolt that passes through a single hole, a U-Bolt wraps around a pipe, tube, bar, or structural member, securing it to a mounting surface when nuts are tightened on each threaded leg. This design distributes clamping load across two points simultaneously, making it a practical choice for pipe-support and clamp applications across many industries.
The defining geometric features of a U-Bolt are its bend radius, leg length, and thread diameter. The bend radius must match—or closely match—the outside diameter of the pipe or section being held, while leg length determines how much thread is available for the mating nuts, washers, and any mounting plate. Accurate Fastners produces U-Bolts in metric thread to standard pitch, ensuring compatibility with widely available nuts and matching hardware across IS, BS, and DIN conventions.
Stainless steel U-Bolts offer corrosion resistance that plain carbon or zinc-plated steel cannot match in damp, chemical, or food-contact environments. Accurate Fastners offers three grades—SS 202, SS 304, and SS 316—to suit varying exposure conditions. The quality control team carries out checks both during raw-material procurement and before dispatch, helping to maintain dimensional accuracy and surface condition in the finished product.
In Depth
Product description
Construction & Geometry
A stainless steel U-Bolt consists of a single rod bent into a symmetrical U-profile, with metric threads cut or rolled onto both legs over a defined thread length. The curved saddle at the top of the bend cradles the pipe or member being supported, while the parallel threaded legs pass through or alongside a mounting bracket or plate. Thread form follows metric conventions, enabling straightforward pairing with standard hex or flange nuts.
Dimensional variables that define one U-Bolt from another include the inside width between legs, the inside height or depth of the bend, the leg length beyond the bend, and the nominal thread diameter. Accurate Fastners covers thread diameters from M3 through M24, providing a broad range suitable for small-bore tubing up to larger structural pipe. Correct inside-width selection is critical: the saddle must suit the outside diameter of the pipe or section it will clamp.
Functional Behaviour in an Assembly
When installed, the U-Bolt saddle contacts the pipe or bar from above while the threaded legs pass through holes in the support plate beneath. Nuts—typically paired with washers—are threaded onto each leg and tightened alternately so that clamping force is applied evenly. This two-point tightening action tends to keep the clamped member centred within the saddle, reducing the likelihood of uneven stress concentration at any single contact area.
The assembly typically includes the U-Bolt itself, two nuts, two washers, and a mounting plate or channel. Torque is applied to the nuts rather than the bolt body, which means the curved section is loaded in tension across the saddle. Proper nut tightening sequence and the use of the correct mating hardware are important for consistent clamping. Consult the relevant IS, BS, or DIN standard for torque guidance appropriate to the thread diameter and grade in use.
How U-Bolts Differ from Similar Fasteners
A U-Bolt is sometimes confused with a J-bolt or an eye-bolt, but each serves a distinct purpose. A J-bolt has only one threaded leg and hooks underneath a structure; an eye-bolt provides a looped head for lifting or cable anchoring. The U-Bolt's symmetric twin-leg design specifically addresses the need to clamp a round or rectangular member from one side while fastening through a plate on the other, without the member needing to have any pre-drilled holes.
Pipe clamps with a hinged or two-piece saddle offer an alternative for situations where the pipe must be removed frequently, whereas a U-Bolt assembly suits more permanent or semi-permanent installations. U-Bolts also differ from foundation bolts in that they are not intended to be cast into concrete or masonry; they are surface-mounted fasteners that rely on nut-and-plate assemblies for their holding action. Accurate Fastners separately supplies pipe clamps alongside U-Bolts for projects requiring both product types.
Material & Grade
Material and grade information
- SS 202
- SS 304
- SS 316
Accurate Fastners offers U-Bolts in three stainless steel grades. SS 202 is an austenitic grade with manganese partially replacing nickel; it is generally more economical and may be considered for indoor or mildly humid environments where budget is a key constraint. SS 304 is among the most widely used austenitic stainless grades globally, typically offering good general corrosion resistance and is commonly found in food processing equipment, water treatment, and general industrial pipework. Grade selection should always account for the specific service environment.
SS 316 incorporates molybdenum, which typically improves resistance to chloride-containing environments and certain chemicals compared with SS 304. It is commonly selected for coastal installations, pharmaceutical-grade pipework, and applications involving saline or mildly acidic media. For any application where the operating environment, chemical exposure, or load conditions are uncertain, consulting the Accurate Fastners sales team is advisable. The team can assist in confirming which grade is most appropriate based on project-specific requirements before an order is placed.
Grades shown are those documented for this product in the Accurate Fastners brochure. General material notes are guidance only; confirm grade selection for your environment.
Technical Data
Technical specifications
| Product type | Bolt – U-Bolt |
|---|---|
| Material | Stainless steel |
| Material grade | SS 202, SS 304, SS 316 |
| Nominal diameter / size | M3 – M24 |
| Length | To be confirmed on enquiry |
| Thread type | Metric |
| Head / form | U-shaped bent bolt, threaded on both legs |
| Drive / tightening | Tightened with nuts |
Sizes
Available sizes
Documented size range
M3 – M24
Documented length range
On enquiry
Individual sizes within the documented range, thread pitches and lengths are confirmed at quotation stage.
Applications
Industrial applications
Water Treatment & RO Systems
U-Bolts may be used to secure pipework, pressure vessels, and tubing runs in RO water purifier assemblies, where stainless steel grades help resist moisture and maintain hygiene in potable-water contact areas.
Solar Energy Installations
In solar mounting structures, U-Bolts can clamp conduit, rails, or cable trays to frames. SS 304 or SS 316 grades are commonly considered for rooftop and ground-mount systems exposed to outdoor weathering.
Food & Beverage Processing
Pipe support and clamp assemblies in food or beverage lines often require smooth, corrosion-resistant fasteners. Stainless U-Bolts may suit process pipework supports where cleanliness and resistance to wash-down conditions are priorities.
Pharmaceutical Machinery
Pharmaceutical production equipment frequently involves stainless pipework that must be firmly supported. U-Bolts in SS 316 are often considered for such environments due to their generally recognised resistance to cleaning agents.
Submersible Pump & LED Lighting Structures
Submersible pump discharge pipes and LED lighting pole assemblies may use U-Bolts to retain pipes or conduit securely, particularly where vibration or continuous fluid flow places demand on pipe-support hardware.
Features & Selection
Features and selection considerations
Design features
Symmetric Dual-Leg Design
Both threaded legs are equal in length and parallel, enabling balanced nut tightening and even load distribution across the mounting plate—a fundamental advantage over single-anchor fastener types.
Metric Thread on Both Legs
Metric thread form across the M3–M24 range ensures direct compatibility with standard metric nuts, washers, and hardware available to IS, BS, and DIN specifications.
Three Stainless Grade Options
Availability in SS 202, SS 304, and SS 316 allows grade selection to be matched to the corrosion demands and budget considerations of each specific project or installation environment.
Broad Diameter Range
Coverage from M3 to M24 accommodates a wide variety of pipe sizes and structural sections, reducing the need to source multiple product families from different suppliers.
Quality-Checked at Procurement and Dispatch
Accurate Fastners' quality control team inspects material and finished product at both inbound and outbound stages, supporting dimensional accuracy and surface integrity of each batch.
Before you order
Match Bend Radius to Pipe OD
The inside width of the U-Bolt saddle should correspond to the outside diameter of the pipe or section being clamped. Confirm the pipe OD before specifying, as an incorrect fit compromises clamping and may damage the pipe surface.
Specify Thread Diameter and Leg Length
Leg length must provide sufficient thread engagement for nuts, washers, and any mounting plate thickness. Provide the required thread diameter (M3–M24) and the net usable leg length when enquiring to avoid fitment issues on site.
Choose Grade for the Environment
SS 202 may suit dry or mildly damp indoor use; SS 304 is common for general industrial and water-contact service; SS 316 is typically preferred where chlorides, chemicals, or outdoor coastal exposure are factors.
Confirm Mating Hardware and Documentation
Confirm whether nuts, washers or mounting plates should be supplied with the U-Bolt, and state the required quantity, grade, documentation and applicable standard (IS, BS or DIN) when you send your enquiry.
FAQs
Frequently asked questions
What is a U-Bolt primarily used for?
A U-Bolt is used to clamp and secure pipes, tubes, bars, or structural members to a supporting surface. Both threaded legs pass through a mounting plate, and nuts tightened on each leg hold the assembly firmly in position.
Which stainless steel grades are available for U-Bolts at Accurate Fastners?
Accurate Fastners supplies U-Bolts in SS 202, SS 304, and SS 316. Each grade offers different corrosion-resistance characteristics. The sales team can help confirm which grade suits your specific operating environment and project requirements.
What diameter and size range is available?
U-Bolts are available in metric thread diameters from M3 to M24. Bend radius, leg length, and inside width vary by application; provide your pipe outside diameter and mounting plate details when placing an enquiry to ensure correct sizing.
Do the U-Bolts comply with any recognised standards?
Accurate Fastners' fastener range is produced in compliance with IS, BS, and DIN standards as applicable. The metric thread form on U-Bolts aligns with these conventions. Confirm the specific standard required for your project when requesting a quotation.
What additional components are typically needed with a U-Bolt?
A complete U-Bolt assembly usually requires two hex nuts, two washers, and a mounting plate or channel. Accurate Fastners also supplies pipe clamps and washers; enquire about companion hardware availability when ordering U-Bolts to ensure full assembly compatibility.
How can I request a quotation or technical assistance?
Submit your requirements—grade, thread diameter, bend radius, leg length, and quantity—via the website enquiry form, email export@accuratefastners.com, or contact Accurate Fastners on WhatsApp. The sales team will respond with pricing and any clarifications needed.
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