Standards
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175 / ISO 15156-2
- NORSOK M-650 Qualified
- API 6A Certified
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Incoloy 925 U-Bolts (UNS N09925)
Round / square / semicircular bend U-bolts for pipe, cable, shaft clamping in sour-service applications
Incoloy 925 U-bolts (UNS N09925) are formed-from-bar fasteners with a U-shape (180° bend) at one end and threaded ends at the other. The U-shape clamps around a pipe, cable, shaft or round structural member; the threaded ends pass through a backing plate or saddle and are tightened with two nuts to lock the clamped item in position. U-bolts are NOT threaded their entire length, only the two parallel ends are threaded, with the curved U-section remaining as smooth bar. The bend radius is matched to the OD of the item being clamped: a 4" pipe U-bolt has a 4" inner-bend radius. TorqBolt manufactures Incoloy 925 U-bolts in M6 to M30 (1/4" to 1-1/4") rod diameter, with bend radii from 10 mm to 250 mm to match common pipe / tube / cable sizes, in the solution-annealed and aged condition with hardness controlled within the 35 HRC NACE MR0175 sour-service cap.
Need Incoloy 925 U-bolts? Email info@torqbolt.com with rod diameter, inner-bend radius (or pipe OD being clamped), thread length per leg, thread series, quantity. WhatsApp +91-22-66157017.
U-Bolt Variants Manufactured
| Variant | Description | Use |
|---|---|---|
| Round-bend U-bolt | Smooth 180° round bend matching pipe OD | Pipe / tube clamping (most common) |
| Square-bend U-bolt | Two 90° bends + flat between, clamps square-section members | Square-section structural / cable-tray clamping |
| Semicircular U-bolt (long-leg) | Round bend with extra-long parallel legs for thick-substrate clamping | Deep-substrate / thick-flange anchoring |
| Hook bolt (J-bolt variant) | One end bent to 90° hook (vs both-end-threaded U) | Single-anchor clamp; door-frame retention |
| Eye bolt (closed-loop alternative) | Closed-loop eye at one end for cable / chain attachment | Lifting + tie-down applications |
Standard Size Range
| Rod Diameter | UNC | Metric Coarse | Common Pipe OD Match | Thread Length per Leg |
|---|---|---|---|---|
| 1/4" / M6 | UNC 20 | M6 × 1.0 | 1/2" to 2" pipe | 20 to 50 mm |
| 3/8" / M10 | UNC 16 | M10 × 1.5 | 1/2" to 4" pipe | 25 to 75 mm |
| 1/2" / M12 | UNC 13 | M12 × 1.75 | 2" to 6" pipe | 30 to 100 mm |
| 5/8" / M16 | UNC 11 | M16 × 2.0 | 4" to 8" pipe | 40 to 120 mm |
| 3/4" / M20 | UNC 10 | M20 × 2.5 | 6" to 12" pipe | 50 to 150 mm |
| 1" / M24 | UNC 8 | M24 × 3.0 | 8" to 16" pipe | 60 to 200 mm |
| 1-1/4" / M30 | UNC 7 | M30 × 3.5 | 12" to 24" pipe | 75 to 250 mm |
Mechanical Properties (Aged)
Tensile 165 ksi min / Yield 110 ksi min / Elongation 18% min / Hardness 32–35 HRC (NACE cap). The bend region experiences forming residual stress; for sour-service applications, the post-bend solution anneal + age cycle restores stress-free metallurgy across the bend. See mech properties page.
Applications
- Sour-service pipe clamping, production tubing / flowline anchorage to support brackets
- Subsea cable clamping, control-line + power-cable retention to riser / J-tube
- Topside pipe-rack support clamping, offshore platform process piping
- Marine structural clamping, mast / spar / boom anchor points
- Cable-tray clamping (square-bend variant), structural-steel attachment
- Drilling-mud line clamping (deck-laid lines)
- Heat-exchanger tube-bundle anchor clamps
Standards
- ASTM B805, UNS N09925 forging stock (input bar)
- Customer drawing, U-bolts are typically supplied to specific drawings (no single ASME / ISO U-bolt standard)
- MSS SP-69, Pipe Hangers and Supports, Selection and Application (reference U-bolt geometry)
- ASME B1.1 / B1.13M, thread tolerance (2A external on threaded legs)
- NACE MR0175 / ISO 15156-3 Table A.10, sour-service qualification
- EN 10204 3.1 / 3.2, certification
Manufacturing Sequence
- Bar input per ASTM B805 in annealed condition (round bar diameter matches U-bolt rod diameter)
- Cut to length: total length = 2 × (leg length + thread reach) + bend allowance
- End thread cutting / rolling on both ends (annealed condition, before bending)
- Cold bending in a forming die to specified inner-bend radius (annealed material accepts cold bend without cracking)
- Solution anneal + age cycle per heat-treatment specification, the post-form anneal removes residual bending stress; age cycle develops strength uniformly
- Final inspection: bend geometry verification, leg-spacing tolerance, thread Go / No-Go, 100% hardness
- Marking: heat number stamped on one threaded end + grade designation + NACE stamp (sour orders); supplied with two matched hex nuts + two flat washers per leg
Frequently Asked Questions
What inner-bend radius should I order? Match the inner-bend radius to the OUTSIDE diameter of the item being clamped. For a 4" Schedule 40 pipe (OD 4.500"), order a 4-1/2" inner-bend U-bolt. The pipe should sit snugly inside the bend without crushing, some clearance allows for insulation or sleeve retrofitting if needed.
Are U-bolts NACE-compliant after the bending operation? Yes, provided the post-bend solution-anneal + age cycle is performed (TorqBolt's standard process). The bending operation introduces cold work + residual stress in the bend region; the 1900°F solution anneal removes both, returning the alloy to a uniform microstructure. The subsequent age cycle then develops the 110 ksi YS uniformly across the U-bolt.
Are nuts and washers supplied with the U-bolt? Yes, standard supply includes 2 matched hex nuts + 2 flat washers per U-bolt (one nut + washer per threaded leg). Alternative components (heavy hex nuts, lock washers, jam-nut configuration) supplied on request.
Lead time? Standard sizes (M10 to M20 / 3/8" to 3/4") for common pipe ODs: 5–7 weeks. Larger / custom-bend-radius / square-bend variants: 8–10 weeks. The bottleneck is the 18-hour age cycle plus the bending die setup for non-standard pipe ODs.
Documentation Package & Related Products
EN 10204 3.1 MTC (3.2 with TPI on request); chemistry, tensile, 100% hardness, bend geometry verification, thread Go/No-Go, NACE MR0175 reference. Supplied with matched nuts + washers. Related: hex nuts, washers, threaded rods (for custom-length anchor-rod fabrication), full datasheet.
Request a Quote
Email info@torqbolt.com · Phone +91-22-66157017 · WhatsApp +91-22-66157017. Specify rod diameter, bend type (round / square / semicircular), inner-bend radius (or pipe OD), thread length per leg, thread series, quantity, applicable standards, MTC level, included companion components.
References: ASTM B805; MSS SP-69 (pipe hangers + supports); ASME B1.1 / B1.13M (thread series); ASME B1.3 (thread gauging); NACE MR0175 / ISO 15156-3 Table A.10; EN 10204; ASTM A380 / A967 (passivation). Special Metals Corporation INCOLOY® alloy 925 Technical Bulletin. INCOLOY® is a registered trademark of Special Metals Corporation.
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