Product Highlights
- Incoloy 925 precipitation hardening nickel alloy solid & hollow shaft, UNS N09925, EN 2.4858, comply with ASTM B805 bar specification
- Ni-Cr-Mo-Cu-Al-Ti precipitation hardening system, adjustable strength via standard single-step aging heat treatment
- Excellent resistance to H₂S sour gas, brine, chloride pitting & sulfide stress cracking (NACE MR0175 certified)
- Balanced anti-corrosion performance between Monel K500 and Inconel 718, cost-effective oilfield alloy
- Stable mechanical property from cryogenic temperature up to 600°C medium high-temperature service
- Two stock options: solid round shaft & seamless hollow shaft, reduce deep boring machining cost for tubular spindles
- Custom OD, ID, wall thickness, length & full CNC turning, boring, threading, splining per CAD drawings
- Core blank for downhole oil & gas, subsea wellhead, chemical desalination & pump rotary components
Product Overview
This series of Incoloy 925 solid and hollow shafts are produced by hot rolling + seamless piercing cold drawing forming process. The standard factory supply base state is Solution Annealed Condition A soft blank for easy CNC machining; customers can perform standard aging treatment to achieve target high tensile and yield strength.
Incoloy 925 is a widely used sour-service precipitation hardening nickel alloy, integrated copper and molybdenum elements to strengthen resistance to reducing acid and chloride media. Different from high-temperature focused Inconel 718, Incoloy 925 is optimized for oil & gas downhole environments with superior anti-SCC performance and lower raw material cost. Solid shaft is applied for solid transmission spindles; seamless hollow shaft avoids heavy deep boring on solid bar, cutting processing cycle and material waste significantly. Widely machined into downhole pump shafts, wellhead valve stems, desalination equipment spindles, chemical agitator rods and marine fixture blanks for petroleum, offshore, chemical and seawater treatment industries.
Material Grade Characteristics – Incoloy 925 (UNS N09925 / 2.4858)
- Ni-Cr-Mo-Cu base alloy strengthened by Al-Ti intermetallic precipitates after aging
- NACE MR0175 compliant, fully resist sulfide stress cracking in high H₂S brine downhole medium
- Dual copper & molybdenum design delivers excellent reducing acid & pitting corrosion resistance
- Soft solution annealed state with great machinability for all CNC turning, boring and threading
- Low thermal deformation after aging, ideal precision downhole rotary parts with tight tolerance
- Good weldability, no post-weld cracking risk, aging can be carried out after welding assembly
Chemical Composition (Weight %)
| Grade |
EN No. |
C ≤ |
Si ≤ |
Mn ≤ |
P ≤ |
S ≤ |
Cr |
Ni Min |
Mo |
Cu |
Ti |
Al |
Fe |
| Incoloy 925 |
2.4858 |
0.03 |
0.50 |
1.00 |
0.015 |
0.010 |
19.5–23.0 |
42.0 |
2.50–3.50 |
1.50–3.00 |
0.60–1.20 |
0.10–0.40 |
Balance |
Mechanical Properties (ASTM B805 Standard Heat Treatment States)
| Delivery State |
Min Tensile MPa |
Min Yield MPa |
Min Elongation % |
Hardness HB Reference |
| Condition A (Solution Annealed) |
760 |
310 |
35 |
≤220 HB |
| Aged Standard (732℃ Single Aging) |
1030 |
725 |
18 |
310–370 HB |
Unified Base Delivery Standard: Hot Rolled / Cold Drawn & Pierced, Solution Annealed (Condition A), Stress‑Relieved, Pickled
Related Material Grades
- Incoloy Series: 800 / 800H / 800HT / 825 / 925
- Inconel Series: 600 / 601 / 625 / 690 / 718 / X-750
- Hastelloy Series: C4 / C22 / C276 / C2000 / B3
- Monel & Pure Nickel: Monel 400 / K500, Nickel 200 / 201
- Duplex Stainless Steel: 2205 / 2507 / S32750
- Austenitic Stainless Steel: 304L / 316L / 321 / 904L
- PH Stainless Steel: 17-4PH / 15-5PH
- Alloy Steel: 4140 / F22 / F91 / A105
Key Advantages
1 Sour Gas Anti-SCC Performance
NACE certified grade, stable service in high H₂S & chloride mixed downhole brine, avoid sulfide cracking failure of ordinary stainless steel.
2 Composite Acid Corrosion Resistance
Copper + molybdenum dual alloy design, outstanding tolerance to sulfuric, phosphoric acid and seawater brine media.
3 Cost Advantage Over Inconel 718
Lower nickel & niobium content, more economical for medium-temperature oilfield rotary components while retaining precipitation hardening capacity.
4 Dual Solid & Hollow Stock Supply
Seamless hollow shaft eliminates deep boring process, reduces material waste and shortens CNC processing cycle for hollow spindles.
5 Low Deformation After Aging
Minimal dimensional shift during precipitation hardening, fit precision valve & pump shafts with tight tolerance requirements.
Typical Applications
- Oil & Gas Downhole: Sour well pump shafts, tubing rotary spindles, wellhead valve stems
- Offshore Subsea: Seawater injection equipment shafts, underwater fixture blanks
- Chemical Industry: Mixed acid reactor agitator rods, desalination pump spindles
- Marine Equipment: Seawater circulation transmission shafts, anti-corrosion fastener blanks
- General Corrosive Machinery: High-pressure medium rotary support rods
Processing Service
We provide integrated hot rolling & seamless piercing hollow shaft production, full custom CNC processing per customer CAD/PDF drawings:
- Fixed-length cutting, centering, external turning, hollow internal boring, chamfering
- Precision threading, spline machining, cylindrical precision grinding & mirror polishing
- Standard single aging heat treatment customization service
- Pickling, passivation anti-corrosion surface finishing
We supply Incoloy 925 solid & hollow shaft blanks and finished machined spindles for petroleum, offshore, chemical and desalination global industrial clients.
Quality Assurance
- 100% UT & Eddy Current dual inspection for rolling & piercing internal segregation and crack defects
- Full batch tensile, yield, elongation & hardness mechanical testing per heat lot
- High-precision micrometer & CMM to control diameter, wall thickness & straightness tolerance
- Spectrometer full-spectrum chemical composition verification per heat number
- Metallographic precipitation phase microstructure inspection after aging heat treatment
Mill Test Certificate EN 10204 3.1 can be issued and delivered together with shipment documents before delivery.
Packing & Delivery
Packing
- Inner: Independent anti-rust plastic sleeve + waterproof film full wrap for surface scratch protection
- Outer: Reinforced fumigated wooden pallet with separation strips to prevent bending & collision damage
- Custom heavy-duty export packaging for extra long/large-diameter shafts available upon request
Lead Time
Normally 10 – 45 working days after receiving advance payment. Exact lead time depends on shaft type (solid/hollow), diameter, length, order quantity and custom aging/machining demands.
