Incoloy 925 Fasteners

Incoloy 925 Fasteners Supplier in Mumbai, India - UNS N09925 / ASTM B637 / B805

Nicorex Alloys is a supplier of Incoloy 925 fasteners based in Mumbai, India. Incoloy 925 is built on the same Ni‑Fe‑Cr‑Mo‑Cu base system but modified to deliver far higher strength. This is achieved by raising titanium to about 1.9-2.4% (vs 0.6-1.2% in 825) and adding 0.1-0.5% aluminium, which together form strengthening γ′ Ni₃(Al, Ti) precipitates within the corrosion‑resistant matrix.

These metallurgical tweaks boost yield strength from roughly 35 ksi in 825 to about 90 ksi (621 MPa) in 925, giving approximately 2.6 times higher load-carrying capacity while retaining resistance to H₂S, CO₂, and chlorides. That combination makes Alloy 925 a go‑to choice for HPHT sour gas wellheads, downhole completion components, and subsea manifold bolting, where both high clamp load and sour‑service corrosion resistance are mandatory. In practice, Incoloy 925 delivers a cost‑effective combination of high strength and sour‑service corrosion resistance for demanding oil and gas applications.

Incoloy 925 fasteners from Nicorex Alloys are produced to UNS N09925 and supplied in accordance with ASTM B637 and ASTM B805. They are qualified to NACE MR0175 / ISO 15156 at a maximum hardness of 35 HRC and typically achieve 860 MPa (125 ksi) tensile strength. The range includes Incoloy 925 hex bolts, stud bolts, socket head cap screws (SHCS), nuts, lock nuts, washers, threaded rods, and eye bolts from M6 to M100 (1/4” to 4”), Charpy impact tested at -60°C and supported by ASME BPVC Code Case 2218 and ISO 9001 / ISO 14001 certifications.

Incoloy 925 Fastener Specifications

The following details define the standards, processing conditions, dimensional range, and performance criteria for Incoloy 925 fasteners:

Standard	ASTM B564 / ASME SB-564
Forms	Bolts, Nuts, Screws, Washers, Studs, Threaded Rods, Hex Bolts, Socket Head Cap Screws, Hex Nuts, Lock Nuts, Stud Bolts
Size	M6 – M100 (Metric); 1/4″ – 4″ (Imperial)
Length	3 mm – 200 mm; Custom lengths available
Diameter	M6 – M100 (Metric); 1/4″ – 4″ (Imperial)
Thread Types	UNC, UNF, Metric Coarse, Metric Fine, BSW, BSF
Surface Finishes	Bright Finish, Pickled, Passivated, Hot-Dip Galvanized, Electropolished
Available Conditions	Solution Annealed, Precipitation Hardened (Aged)

Chemical Composition of Incoloy 925 Fasteners

Chemical composition requirements for Incoloy 925 fasteners, defined for the alloy grade corresponding to UNS N09925 material designation:

Element	Nickel (Ni)	Chromium (Cr)	Iron (Fe)	Molybdenum (Mo)	Copper (Cu)	Titanium (Ti)	Aluminium (Al)	Carbon (C)	Manganese (Mn)
Composition (%)	42.0-46.0	19.5-23.5	Balance (~22)	2.5-3.5	1.5-3.0	1.9-2.4	0.1-0.5	0.03 max	1.0 max

The higher Ti (1.9-2.4% vs 825’s 0.6-1.2%) and added Al (0.1-0.5%) enable γ′ Ni₃(Al, Ti) precipitation hardening, the same mechanism used in Inconel 718, but in a corrosion-optimised matrix. Lower C (0.03% vs 825’s 0.05%) further reduces sensitisation risk in the aged condition.

Mechanical Properties of Incoloy 925 Fasteners

Mechanical properties of Incoloy 925 fasteners in the solution-annealed and aged condition, determined using standard procedures for this alloy grade:

Property	Tensile Strength (min)	Yield 0.2% (min)	Elongation (min)	Reduction of Area (min)	Hardness (NACE max)
Value	860 MPa (125 ksi)	621 MPa (90 ksi)	20%	25%	35 HRC

Per ASTM B637, solution annealed + aged:A single M24 Incoloy 925 stud bolt delivers 2.6× the clamp load of an M24 Incoloy 825 stud (90 ksi vs 35 ksi yield). This directly reduces flange dimensions and equipment weight for deepwater well completions.

Incoloy 925 Fastener Equivalent Grades

Incoloy 925 fasteners have multiple equivalent designations across international standards, helping engineers cross-reference grades and ensure correct global material selection:

Standard System	UNS	Werkstoff Number
Equivalent Grade	N09925	2.4858

Premium Industrial Materials

Get Incoloy 925 Fasteners at Competitive Prices

ISO Certified

Custom Sizes

Fast Delivery

Get a Quote

Types of Incoloy 925 Fasteners Available

A wide range of Incoloy 925 fasteners is available to meet the demands of high-pressure, sour-service applications.

Incoloy 925 Hex Bolts / Heavy Hex Bolts - ASME B18.2.1, DIN 931/933

925 Stud Bolts - Double-end per ASME B16.5, critical for wellhead flange bolting

Alloy 925 Socket Head Cap Screws - ASME B18.3

Incoloy 925 Hex Nuts / Heavy Hex Nuts - ASME B18.2.2

925 Lock Nuts - All-metal prevailing torque (high-temp service)

Alloy 925 Flat Washers / Hardened Washers

Incoloy 925 Threaded Rods

925 Eye Bolts / Anchor Bolts

Sour Gas Downhole Bolting & Age-Hardened Corrosion Performance

Incoloy 925 was purpose-built to combine age-hardened strength with sour-gas corrosion resistance. The γ′ Ni₃(Al, Ti) precipitation produces 125 ksi tensile / 90 ksi yield while maintaining full NACE MR0175 compliance at ≤35 HRC. The 42-46% Ni provides immunity to sulfide stress cracking (SSC) in H₂S-containing environments at pressures representative of deep sour gas wells.

High nickel content also prevents chloride SCC that would destroy duplex or super duplex bolting in hot brine environments encountered downhole. The Mo + Cu combination resists pitting and crevice corrosion in produced fluids around bolted connections.

925 vs 825: Use 825 when yield ≤35 ksi is sufficient, and cost is a priority. Use 925 when yield >60 ksi is required for HPHT wells, weight reduction, or API 6A compliance. 925 vs 718: Use 925 when sour-gas corrosion is the primary driver. Use 718 when 185 ksi tensile is required, regardless of corrosion. Not recommended above 540°C (over-ageing begins).

Surface Finish and Coating Options

Plain: Standard (most common for oil & gas aged bolting)
Passivated: Citric acid passivation per ASTM A967
Manganese Phosphate: Thread lubricity for high-torque assembly
Anti-Seize: Nickel-based recommended – copper-based acceptable

NOTE: PTFE/Xylan coatings are suitable for moderate-temperature sour service. Zinc-based coatings are NOT recommended (hydrogen evolution risk in sour environments).

Industries and Applications for Incoloy 925 Fasteners

Incoloy 925 fasteners provide high-strength, sour-service corrosion resistance for upstream oil and gas, subsea production systems, and high-pressure chemical processing.

Oil and gas (upstream): Sour gas wellhead stud bolts, HPHT completion equipment bolting, Christmas tree flange studs, downhole safety valve fasteners, tubing hanger hardware, BOP bolting.
Subsea production: Subsea manifold bolting, flowline connector studs, subsea tree fasteners where weight reduction vs 825 is critical.
Chemical processing: High-strength acid service bolting for H₂SO₄ and H₃PO₄ environments.
High-pressure piping: Sour-service pipeline flange bolting and pump shaft components for HP systems.
Valve system: Valve stem bolting designed for sour-service and high-pressure operation.

How to Order Incoloy 925 Fasteners from Nicorex Alloys

To order Incoloy 925 Fasteners, follow these 12 important details:

Fastener Type - Hex Bolt, Stud Bolt, Socket Head Cap Screw, Nut, Washer, Threaded Rod, Anchor Bolt
Size - Diameter × Length in mm or inches
Thread Type - UNC, UNF, BSW, Metric Coarse/Fine
Material Grade - Incoloy 925 / UNS N09925
Standard - ASTM F468 / ASTM F467 / API 6A
Finish - Bare, Passivated, Pickled
Condition - Solution Annealed & Age-Hardened
Quantity - Number of Pieces or kg
Additional Requirements - NACE MR0175 compliance, specific heat numbers, downhole / sour gas service
Documentation - MTC 3.1 per EN 10204, PMI report, third-party inspection certificate
Packaging - Standard wooden box / export-grade sea-worthy packing / ISPM 15 compliant
Delivery Destination - Domestic / International

Frequently Asked Questions

What is the price of Incoloy 925 Fasteners per Kg in India?

Prices range from ₹3,500 to ₹7,500/kg. Precipitation hardening adds 15-20% over the 825 base cost. Oil and gas NACE-certified fasteners with full 3.2 MTCs, Charpy testing, and TPI documentation command the highest premiums.

What is the difference between Incoloy 925 and Incoloy 825?

Same base chemistry (Ni-Fe-Cr-Mo-Cu), but 925 has higher Ti (1.9-2.4% vs 0.6-1.2%) and added Al (0.1-0.5%), enabling precipitation hardening. Result: 125 ksi tensile / 90 ksi yield vs 825’s 85 ksi / 35 ksi. Choose 825 for general acid service at a lower cost. Choose 925 when high bolt preload is required in the same corrosive environment.

Is Incoloy 925 listed in NACE MR0175?

Yes. UNS N09925 is approved per NACE MR0175 / ISO 15156 for sour service in the SA+Aged condition. Max hardness: 35 HRC, stricter than Inconel 718’s 40 HRC. Every 925 sour-service fastener must ship with hardness-verified EN 10204 3.1/3.2 MTCs.

Why was Incoloy 925 developed?

To fill the gap between solution-annealed 825 (excellent corrosion, low strength) and Inconel 718 (extreme strength, less sour-gas optimised). The oil and gas industry needed high-strength bolting purpose-built for HPHT sour wells.

Can Incoloy 925 replace Inconel 718 in sour service?

In many cases, yes. 925 provides better H₂S + CO₂ + chloride corrosion resistance than 718 at a lower cost. However, 718’s 185 ksi tensile strength is necessary where ultra-high preload is required. For wellhead bolting below 15,000 psi, 925 is often the better choice.

What Charpy Impact Temperature is standard for Incoloy 925 Bolting?

Per SMC specification HA 46, Charpy V-notch testing is performed at -60°C (-75°F) per ASTM E23. This confirms suitability for cold-climate and deepwater service.

What is the Maximum Service Temperature for Incoloy 925 Fasteners?

925 maintains precipitation-hardened properties up to approximately 540°C (1000°F). Above this, γ′ precipitates coarsen and strength drops. For sustained service above 540°C, use Inconel 718 (stable to 700°C).