Unifit Fastener — Incoloy 925 Stud Bolt Manufacturers | Suppliers | Stockists | Exporters in Mumbai, India
Serving 70+ countries with ASTM B805 / ASME SB805 certified fasteners since 2008.
Incoloy 925 Stud Bolt are high performance threaded fasteners that are made of a nickel-iron-chromium alloy containing molybdenum, copper, titanium and aluminium for precipitation hardening. These specially engineered stud bolts are immune to chloride stress corrosion cracking, pitting, crevice corrosion and hydrogen embrittlement, offering unsurpassed reliability in the harshest industrial applications, such as deep sea oil and gas wells, offshore platforms, chemical reactors and nuclear steam generators.
We are Unifit Fastener to produce Incoloy 925 Stud Bolt according to ASTM B805 and ASME SB805 standard. Each batch is solution-annealed and precision aged at 1010°C (1850°F) to ensure the most desirable combination of tensile strength, corrosion resistance and dimensional stability. Unifit Fastener has over 15 years of manufacturing experience and modern manufacturing facilities in Mumbai, India, making them a trusted partner for procurement teams across the globe in the oil & gas, marine, aerospace, and chemical processing industries. We provide a full range of bolt and stud options and/or can supply custom-made flange bolting that is manufactured to meet your specification, on time, every time!
Request a QuoteIncoloy 925 (UNS N09925) is a precipitation-hardenable nickel-iron-chromium alloy designed to withstand sour gas service in downhole applications, valve stems, pump shafts and tubular connections. High nickel and chromium content gives this alloy good resistance to both oxidising and reducing corrosive atmospheres and molybdenum and copper additions greatly improve resistance to pitting and crevice corrosion in chloride-rich environments.
Unlike most standard stainless or nickel alloys, heat treatment is a way of strengthening Incoloy 925, in addition to cold working, and complex bolt geometries are not affected by the process. Incoloy 925 Stud Bolt has this property, which makes it the preferred material when combining high strength and maximum corrosion resistance is essential.
| Property | Details |
|---|---|
| Grade / Alloy | Incoloy 925 (UNS N09925) |
| ASTM / ASME Standards | ASTM B805 / ASME SB805, ASTM B166 / ASME SB166 |
| Size Range (Metric) | M2 to M160 | Custom Sizes on Request |
| Size Range (Inch) | 3/8" to 4" | Custom Sizes on Request |
| Length | 3 mm to 500 mm | Custom Lengths Available |
| Thread Forms | UNF, BSW, BSF, METRIC, UNC, or as required |
| Thread Configuration | ASME B1.1 (2A/3A), 2B/3B Unified; B1.13M (6h-6G) Metric Coarse |
| Forms / Types | Hex, Threading, Square, Round as per gauge |
| Certification | Dual Certified per ASTM & ASME Codes |
| Raw Material Source | JSPL, Mukund Steel, Tata Steel, Dhamm Steel, Usha Martin |
| Test Certificate | EN 10204 / 3.1 Manufacturer Test Certificate |
| Additional Certifications | PED 97/23/EC, Merkblatt AD 2000 W2 |
| Production Process | M24-M100: Hot Forging; M2-M24: Cold Forging; Custom: CNC Machining |
| Element | Ni | Cr | Fe | Mo | Cu | Ti | Al | C (max) | Mn (max) | S (max) | Si (max) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Min % | 42.0 | 19.5 | 22.0 | 2.5 | 1.5 | 1.9 | 0.1 | - | - | - | - |
| Max % | 46.0 | 22.5 | Bal. | 3.5 | 3.0 | 2.4 | 0.50 | 0.030 | 1.00 | 0.030 | 0.50 |
| Condition | Tensile Strength (MPa) | Yield Strength 0.2% Offset (MPa) | Elongation (%) | Hardness | Density (g/cm3) | Melting Point (°C) |
|---|---|---|---|---|---|---|
| Solution Annealed + Aged | 965-1100 | 690-855 | 20-35% | 95 HRB-32 HRC | 8.09 | 1290-1370 |
| Hot Worked | 695 min | 295 min | 35% min | Max 35 HRC | 8.09 | 1290-1370 |
| Standard | UNS | JIS | WERKSTOFF NR. | AFNOR | EN | BS | GOST |
|---|---|---|---|---|---|---|---|
| Incoloy 925 | N09925 | NCF 925 | 2.4856 | NC22DNB4M | NiCr22Mo9Nb | NA 21 | XH75M6TIO |
| NPS | OD of Flange (in) | Bolt Circle Dia (in) | No. of Bolts | Bolt Dia (in) | RF Length (in) | RJ Length (in) |
|---|---|---|---|---|---|---|
| 1/2 | 3-1/2 | 2-3/8 | 4 | 1/2 | 2-1/4 | - |
| 3/4 | 3-7/8 | 2-3/4 | 4 | 1/2 | 2-1/2 | - |
| 1 | 4-1/4 | 3-1/8 | 4 | 1/2 | 2-1/2 | - |
| 1-1/2 | 5 | 3-7/8 | 4 | 1/2 | 2-3/4 | 3-1/4 |
| 2 | 6 | 4-3/4 | 4 | 5/8 | 3-1/4 | 3-3/4 |
| 3 | 7-1/2 | 6 | 4 | 5/8 | 3-1/2 | 4 |
| 4 | 9 | 7-1/2 | 8 | 5/8 | 3-1/2 | 4 |
| 6 | 11 | 9-1/2 | 8 | 3/4 | 4 | 4-1/2 |
| 8 | 13-1/2 | 11-3/4 | 8 | 3/4 | 4-1/4 | 4-3/4 |
| 10 | 16 | 14-1/4 | 12 | 7/8 | 4-1/2 | 5 |
| 12 | 19 | 17 | 12 | 7/8 | 4-3/4 | 5-1/4 |
| 16 | 23-1/2 | 21-1/4 | 16 | 1 | 5-1/4 | 5-3/4 |
| 20 | 27-1/2 | 25 | 20 | 1-1/8 | 6-1/4 | 6-3/4 |
| 24 | 32 | 29-1/2 | 20 | 1-1/4 | 6-3/4 | 7-1/4 |
| Flange Size | Bolt Size | 1st Torque (ft-lbs) | 2nd Torque (ft-lbs) | Final Torque (ft-lbs) | Bolt Pattern |
|---|---|---|---|---|---|
| 1/2" | 1/2" | 10 | 20 | 30 | 4-bolt |
| 1" | 1/2" | 15 | 30 | 50 | 4-bolt |
| 2" | 5/8" | 40 | 80 | 120 | 4-bolt |
| 3" | 5/8" | 40 | 80 | 120 | 4-bolt |
| 4" | 5/8" | 40 | 80 | 120 | 8-bolt |
| 6" | 3/4" | 60 | 120 | 200 | 8-bolt |
| 8" | 3/4" | 60 | 120 | 200 | 8-bolt |
| 10" | 7/8" | 95 | 190 | 320 | 12-bolt |
| 12" | 7/8" | 95 | 190 | 320 | 12-bolt |
| 16" | 1" | 147 | 294 | 490 | 16-bolt |
| 18" | 1-1/8" | 213 | 426 | 710 | 16-bolt |
| 24" | 1-1/4" | 300 | 625 | 1,000 | 20-bolt |
The superior corrosion resistance and high-strength profile of Incoloy 925 Stud Bolt make them the material of choice across multiple demanding sectors:
| Industry | Specific Application |
|---|---|
| Oil & Gas (Upstream) | Wellhead equipment, Christmas tree valves, downhole tubing hangers, sour gas service |
| Offshore & Marine | Subsea connectors, riser clamps, offshore platform bolting, seawater heat exchangers |
| Chemical Processing | Reactor vessels, pressure vessel flanges, corrosive-media handling equipment |
| Power Generation | Steam generator tubing fasteners, nuclear plant components, turbine casing bolts |
| Aerospace | Aircraft engine fasteners, airframe structural bolts, high-temperature nacelle components |
| Desalination Plants | High-chloride environment flanges, pump shaft fasteners |
| Pharmaceutical | Sanitary process equipment, autoclave fasteners requiring clean passivated surfaces |
| Marine Engineering | Propeller shaft studs, hull plate fastenings, underwater pipeline flanges |
| Coating Type | Application / Benefit |
|---|---|
| PTFE (Teflon) Coating | Low friction; prevents galling during assembly; FDA-compliant for food-grade |
| Phosphate Coating | Corrosion inhibition under oil; common in automotive and heavy machinery |
| Hot Dip Galvanizing (HDG) | Thick zinc layer for atmospheric and mild corrosion protection |
| Zinc Plating (BZP) | Bright finish; mild corrosion protection; cosmetically clean |
| Cadmium Coating | Aerospace-grade corrosion protection; excellent in marine environments |
| Dacromet / DACROMET | Geometrically applied inorganic zinc coating; superior to HDG in thin-film form |
| Anodizing | Aluminium-component surface hardening and colour coding |
| Black Oxide | Mild corrosion protection; reduced light reflection; aesthetic finish |
| Xylon Coating | Advanced polymer topcoat for chemical and UV resistance |
| Description | Standard | System |
|---|---|---|
| Continuous Thread Stud Bolts | ANSI/ASME B18.31.2 | Inch |
| Stud Bolts for Flange Bolting (Chamfered End) | ANSI/ASME B16.5 | Inch |
| Welding Studs / Weld Studs | DIN 525 | Metric |
| Double End Stud Bolts | DIN 835 | Metric |
| Double End Studs (Thread Engagement = 1xD) | DIN 938 | Metric |
| Double End Studs (Thread Engagement = 1.25xD) | DIN 939 | Metric |
| Double End Studs (Thread Engagement = 2.5xD) | DIN 940 | Metric |
| Double End Studs (Thread Engagement = 2xD) | DIN 949-1 | Metric |
| Plain End Stud Bolts / Threaded Rods | DIN 975 / DIN 976 | Inch / Metric |
| Double End Stud Bolts / Stud Bolts | DIN 2509 | Metric |
| Double End Bolts with Reduced Shank | DIN 2510 L/Z/K/U/GP/GQ/GR/GS/HP | Metric |
| Studs / Stud Bolts (Inch) | BS 2693 | Inch |
| Stud Bolts | BS 3692 / IS 1862 / IS 13218 | Metric |
Every Incoloy 925 Stud Bolt leaving Unifit Fastener's facility undergoes a rigorous multi-stage quality inspection process aligned with international standards:
Pricing for Incoloy 925 Stud Bolt is influenced by global nickel market rates, size, quantity, and finishing requirements. As a direct manufacturer with in-house forging and machining, Unifit Fastener offers highly competitive FOB pricing:
| Product | Indicative FOB Price Range (USD) |
|---|---|
| Incoloy 925 Stud Bolt M12-M24 (Standard) | USD 1.00-USD 8.00 / piece |
| Incoloy 925 Stud Bolt M30-M64 (Standard) | USD 8.00-USD 45.00 / piece |
| Incoloy 925 Double Ended Stud (Custom) | USD 5.00-USD 60.00 / piece |
| Incoloy 925 Heavy Hex Stud Bolt (Large Diameter) | USD 30.00-USD 150.00 / piece |
| Bulk Order (100 kg+) | Contact Unifit Fastener for best pricing |
Note: Prices are indicative and subject to change based on LME nickel rates. Contact Unifit Fastener's sales team for a firm quotation within 24 hours.
| Property | Incoloy 925 | Inconel 625 | Hastelloy C276 | Super Duplex 2507 | Monel 400 |
|---|---|---|---|---|---|
| UNS No. | N09925 | N06625 | N10276 | S32750 | N04400 |
| Ni Content | 42-46% | 58% min | 57% min | 7% | 63-70% |
| Key Strength | Precipitation hardening | High temp strength | Reducing media | Chloride resistance | Seawater resistance |
| SSC Resistance | Excellent | Good | Very Good | Good | Moderate |
| Temp Limit (°C) | 650 | 1100 | 1040 | 300 | 480 |
| Relative Cost | Moderate-High | High | Very High | Moderate | Moderate |
Incoloy 925 carries the UNS designation N09925. It is also referenced as NCF 925 under the JIS standard and Werkstoff Nr. 2.4856 under the German DIN system.
The primary manufacturing standard is ASTM B805 / ASME SB805. Bolting standards include ASTM B166 / ASME SB166 for rods and bars, and dimensional standards such as ASME B16.5 (flange bolting), DIN 835/938/939/940 (double-ended studs), and IS 1862 (Indian standard).
The most critical applications are in the oil & gas sector - particularly in sour gas wells and downhole equipment - followed by offshore marine engineering, chemical processing reactors, nuclear power plant steam generators, and aerospace structural components where both high strength and corrosion resistance are essential.
Incoloy 925 Stud Bolt are rated for continuous service up to approximately 650°C (1200°F), after which creep and oxidation resistance may diminish. For ultra-high-temperature service above 800°C, Inconel 718 or Inconel 625 may be more appropriate.
Incoloy 925 achieves SSC resistance through its high nickel content (42-46%) combined with controlled precipitation hardening. The hardness ceiling of 35 HRC (per NACE MR0175) is maintained during heat treatment, preventing the embrittlement threshold that makes lower-alloy steels susceptible to SSC in H2S-rich environments.
Unifit Fastener supplies Incoloy 925 Stud Bolt in UNF (Unified Fine), UNC (Unified Coarse), BSW, BSF, and Metric (ASME B1.13M 6h-6G coarse). Custom thread profiles including ACME, Trapezoidal, and NPT are available on request.