U Bolt Manufacturer in India
Lohar Forging & Engg. Works manufactures round-bend, square-bend and drawing-based U bolts in Mumbai for pipe support, structural restraint, automotive and equipment applications. Material, bend geometry, thread and finish are confirmed against the buyer’s service conditions.
Since 2007
Manufacturing experience
Round / Square
Bend options
SS / HDG
Material and finish
Custom
Pipe and leg sizes
Quick answer
What is a U bolt?
A U bolt is a bent rod with threaded legs used to clamp, support or restrain pipe, tube, cable and structural members. Round bends suit circular pipe, while square bends fit rectangular sections and rails. Correct selection depends on pipe outside diameter, rod size, leg length, bend radius, material, coating and the loads imposed by the support system.
U bolt types we manufacture
The assembly can be supplied as a U bolt alone or with compatible nuts, washers and a project-specific backing or saddle plate.
Round Bend U Bolt
Formed to match a specified pipe outside diameter for general pipe support, restraint, hanger and clamp assemblies.
Square Bend U Bolt
Designed for SHS, RHS, channel, rail and rectangular members where leg spacing and inside dimensions are controlled.
Heavy-Duty U Bolt
Larger rod diameters and project-specific material grades for high-load or vibration-sensitive support arrangements.
Automotive U Bolt
Leaf-spring and chassis clamping patterns manufactured to the vehicle or assembly drawing and required grade.
J Bolt / Anchor Pattern
Hooked or anchor-style threaded rods for concrete, base-plate and equipment-fixing applications.
U Bolt Assembly Kit
U bolt with matching nuts, washers, backing plate, saddle or isolating liner when included in the approved specification.
From enquiry to dispatch
How custom U bolts are developed and manufactured
U bolt accuracy depends on the relationship between the supported member, bend geometry, two threaded legs and mating hardware. A complete drawing or measurement schedule reduces assembly problems at site.
- 01
Requirement review
We review pipe outside diameter or member dimensions, rod size, inside width and height, leg and thread length, material, finish, quantity, load function and any plate, saddle or liner. Nominal pipe size is cross-checked against actual OD.
- 02
Drawing confirmation
A manufacturing drawing or agreed dimensional schedule establishes the measurement datum, bend radius, thread length, leg parallelism, tolerances and hardware arrangement. This is especially important for insulated pipe and square structural members.
- 03
Material preparation
Rod stock is selected and cut with allowance for the bend and finished leg dimensions. Grade, heat or batch traceability is maintained when certification is part of the purchase requirement.
- 04
Thread production
Threads are rolled or cut according to material, diameter, quantity and specification. Thread gauges, run-out, usable length and compatibility with the selected nut are checked before or after bending as the process requires.
- 05
Controlled bending
The rod is formed around dedicated tooling to achieve the required round or square geometry without unacceptable flattening, cracking or leg misalignment. Spring-back and material work-hardening are considered during setup.
- 06
Finish and final inspection
After cleaning and the specified finish, final checks cover inside dimensions, leg length, parallelism, thread condition, hardware fit and coating. Agreed documents and packing identification accompany the released batch.
U bolt material and finish guide
The best option depends on corrosion category, temperature, supported-pipe material, strength, forming behaviour, coating compatibility and maintenance. Insulation or liners may also be needed to control contact and galvanic effects.
Hot-Dip Galvanised Mild Steel
A widely used outdoor and infrastructure option where a zinc coating provides sacrificial corrosion protection. Thread allowance, coating thickness, nut fit and any repair of damaged coating must be considered. Common consideration: outdoor pipe racks and construction
Stainless Steel 316 / 316L
Often specified for coastal, marine, wash-down or chemically aggressive locations. Galling control, compatible nuts, isolation from dissimilar metals and the exact corrosion environment should be reviewed. Common consideration: chloride and hygiene-sensitive service
Stainless Steel 304
Suitable for many indoor and moderate-corrosion installations where chloride exposure is limited. It offers a clean stainless finish but should not be assumed suitable for every coastal or process environment. Common consideration: indoor general stainless support
Alloy / High-Strength Steel
Considered for compact, dynamic or high-load assemblies. Grade, heat treatment, bend radius, fatigue, coating route, hydrogen-embrittlement risk and matching nuts require controlled specification. Common consideration: automotive and engineered restraints
Technical comparison
Round bend vs square bend vs heavy-duty U bolts
Bend shape should match the supported member and the connection design. A U bolt that physically fits may still be unsuitable for the applied load, temperature movement or vibration.
| Selection factor | Round bend | Square bend | Heavy-duty / engineered |
|---|---|---|---|
| Supported member | Circular pipe, tube, cable bundle or round axle. | SHS, RHS, channel, rail or rectangular member. | Large pipe, dynamic equipment, structural restraint or project-specific assembly. |
| Key dimensions | Pipe OD, rod diameter, inside width/height, leg and thread length. | Member width/depth, inside corner radius, leg spacing and length. | Full drawing, load cases, material grade, hardware, plate/saddle and installation detail. |
| Design concern | Uniform fit without crushing coating, insulation or pipe wall. | Corner stress, bend radius, member edge contact and leg parallelism. | Strength, fatigue, vibration, thermal movement, preload and inspection requirements. |
| Typical purchasing error | Ordering from nominal bore without confirming actual pipe OD or insulation. | Using round-bend dimensions or ignoring the member corner radius. | Increasing rod diameter without engineering the plate, nuts, base member and load path. |
Quality and traceability
Dimensional control and supply documentation
Two U bolts with the same nominal description can fit very differently. Repeatable dimensions, compatible hardware and documented material/finish are therefore central to supplier evaluation.
- ✓ Material grade and heat or batch information can be recorded when traceability is included in the order.
- ✓ Inside width, inside height, leg length, thread length, bend radius and leg parallelism are checked against the approved drawing.
- ✓ Thread gauges and trial nut fit help identify coating buildup, damaged threads or incorrect pitch before dispatch.
- ✓ Coating and finish requirements may include visual condition, agreed thickness records and handling protection.
- ✓ Assembly-kitted orders can be checked for correct nut, washer, plate, saddle and liner quantities before packing.
Technical overview
U bolt specifications
| Parameter | Available / project-specific options |
|---|---|
| Reference standards | DIN 3570, BS 3974, IS 6610 or project-specific pipe-support requirements can be reviewed and confirmed on quotation. |
| Pipe / member size | Round-bend inside diameter is matched to the stated pipe OD; square-bend width and depth follow the structural member. |
| Rod and thread | Metric and selected imperial rod/thread options, with leg length and thread length made to drawing. |
| Materials | Mild steel, SS 304, SS 316/316L and selected alloy grades depending on forming, load and environment. |
| Surface finish | Self-colour, electro-zinc, hot-dip galvanised, stainless finish or specified protective coating. |
| Dimensional control | Inside width, leg parallelism, bend radius, leg length and thread are inspected against the approved drawing. |
| Supply format | U bolt only or assembly with nuts, washers, backing plate, saddle and isolating insert. |
Engineering and safety note: Dimensions, material grades, loads, torque values and standards must be confirmed for the exact product, installation and duty. Do not select safety-critical hardware solely from general website information.
How to specify a U bolt
Provide actual pipe or member dimensions rather than relying only on nominal pipe size; insulation and coating thickness can change the required inside dimensions.
Geometry
State pipe OD or member width/depth, rod diameter, inside width, inside height, leg length and thread length.
Service load
Describe whether the assembly restrains weight, uplift, vibration, thermal movement, shock or structural pull-out.
Material / finish
Identify outdoor, coastal, chemical, high-temperature, cryogenic or galvanic-corrosion constraints.
Assembly details
Confirm nuts, washers, plate or saddle, liner, torque procedure, installation clearance and required certificates.
U bolt applications by industry
Oil, Gas & Process
Pipe racks, instrument lines, insulated-pipe supports and maintenance restraint assemblies.
Shipbuilding & Offshore
Engine-room piping, cable trays, marine equipment and corrosion-resistant supports.
Automotive
Leaf-spring assemblies, exhaust supports and drawing-based chassis clamping.
Construction & MEP
Fire, plumbing, HVAC, conduit and structural service supports.
Solar & Infrastructure
Rail, pole, sign, frame and mounting-member clamping for outdoor projects.
Agriculture & Equipment
Implement frames, hose restraints, brackets and machinery support assemblies.
Why buyers contact Lohar Forging
Drawing-based production
Inside dimensions, leg length, thread and bend radius can be controlled to the approved requirement.
Round and square capability
Pipe and structural-member configurations can be reviewed within one manufacturing source.
Material choice
Stainless, mild-steel, galvanised and alloy routes are assessed for environment and application.
Assembly supply
Nuts, washers, plates, saddles and liners can be considered as part of the complete requirement.
Dimensional inspection
Critical geometry and thread details can be documented when specified before order.
Bulk and export enquiries
Production quantities, packing and delivery documentation can be planned with the quote.
Frequently Asked Questions
What measurements are required for a custom U bolt?+
Provide pipe outside diameter or member dimensions, rod diameter, inside width and height, overall leg length, thread length and pitch, material, finish, quantity and any plate or saddle details. A marked drawing is the clearest input.
Should I choose hot-dip galvanised or stainless U bolts?+
The choice depends on corrosion exposure, required strength, temperature, compatibility with the supported member, inspection regime and project specification. Coastal or chemical service often needs a specifically approved corrosion-resistant grade.
Can U bolts be used for structural applications?+
Yes, square and custom patterns are used for structural clamping, but the connection must be engineered for the relevant load, slip, fatigue, member strength and installation details. Do not infer structural capacity from rod diameter alone.
Do you supply nuts, washers and saddle plates?+
Yes, these can be included when stated in the enquiry. Confirm nut grade, washer type, plate geometry, material, coating and whether an isolating liner is required.
What installation torque should be used?+
There is no single universal torque. It depends on diameter, thread, material, grade, coating, lubrication, nut system and the supported component. Use the approved engineering or supplier torque procedure for the exact assembly.
What is the difference between nominal pipe size and pipe outside diameter?+
Nominal bore or DN is a naming system and is not always the physical outside diameter. A U bolt must be made to the actual pipe OD plus any coating, insulation, liner and installation clearance. Always provide OD or the governing pipe standard.
When should a square bend U bolt be used?+
Square bends are generally used around rectangular or square members such as SHS, RHS, rail, channel or mounting frames. Inside width, depth and corner radius should match the member without damaging its surface or concentrating load at an unintended point.
How should insulation be considered when ordering pipe U bolts?+
State pipe OD, insulation thickness, cladding thickness and whether the U bolt bears on the pipe, an insulation shield, a saddle or an isolating liner. The support design should prevent crushing insulation and unwanted metal-to-metal contact.
Get a project-specific quotation
Share size, drawing, material, finish, quantity, documentation and delivery requirements for technical review.
Quick Summary
Lohar Forging manufactures round-bend, square-bend and drawing-based U bolts in Mumbai for pipe support, structural restraint, automotive and equipment applications.
Key Takeaways
- ▸Round, square and heavy-duty U bolt configurations
- ▸Stainless steel, mild steel, HDG and alloy material routes
- ▸Custom pipe dimensions, leg lengths, threads and assembly options
Frequently Asked Questions
What measurements are required for a custom U bolt?+
Provide pipe outside diameter or member dimensions, rod diameter, inside width and height, overall leg length, thread length and pitch, material, finish, quantity and any plate or saddle details. A marked drawing is the clearest input.
Do you supply nuts, washers and saddle plates?+
Yes, these can be included when stated in the enquiry. Confirm nut grade, washer type, plate geometry, material, coating and whether an isolating liner is required.
What installation torque should be used?+
There is no single universal torque. It depends on diameter, thread, material, grade, coating, lubrication, nut system and the supported component. Use the approved engineering or supplier torque procedure for the exact assembly.
Should I choose hot-dip galvanised or stainless U bolts?+
The choice depends on corrosion exposure, required strength, temperature, compatibility with the supported member, inspection regime and project specification. Coastal or chemical service often needs a specifically approved corrosion-resistant grade.
Can U bolts be used for structural applications?+
Yes, square and custom patterns are used for structural clamping, but the connection must be engineered for the relevant load, slip, fatigue, member strength and installation details. Do not infer structural capacity from rod diameter alone.
What is the difference between nominal pipe size and pipe outside diameter?+
Nominal bore or DN is a naming system and is not always the physical outside diameter. A U bolt must be made to the actual pipe OD plus any coating, insulation, liner and installation clearance. Always provide OD or the governing pipe standard.
When should a square bend U bolt be used?+
Square bends are generally used around rectangular or square members such as SHS, RHS, rail, channel or mounting frames. Inside width, depth and corner radius should match the member without damaging its surface or concentrating load at an unintended point.
How should insulation be considered when ordering pipe U bolts?+
State pipe OD, insulation thickness, cladding thickness and whether the U bolt bears on the pipe, an insulation shield, a saddle or an isolating liner. The support design should prevent crushing insulation and unwanted metal-to-metal contact.