Product Highlights
- Inconel 718 precipitation hardening nickel alloy solid & hollow shaft, UNS N07718, EN 2.4668, compliant with ASTM B637 bar standard
- Nb-Al-Ti precipitation strengthening system, adjustable high strength via standard H925 / H1040 double aging heat treatment
- Retain excellent tensile, creep & fatigue strength up to 704°C high-temperature continuous operation
- Outstanding resistance to chloride SCC, sour H₂S gas, seawater and mixed acid media, NACE MR0175 certified
- Stable low-temperature toughness down to cryogenic -200℃ without brittle transition
- Two stock options: solid round shaft & seamless hollow shaft to eliminate deep boring machining cost
- Custom diameter, wall thickness, length & full CNC turning, boring, threading, splining per CAD drawings
- Core rotary blank for aerospace turbine, subsea wellhead, nuclear power & high-temperature chemical equipment
Product Overview
This series of Inconel 718 solid and hollow shafts are manufactured by hot rolling + seamless piercing cold drawing forming. Standard supply base state is Solution Annealed Condition A soft blank for easy CNC machining; customers can perform standard double aging treatment to achieve ultra-high tensile and creep strength.
Inconel 718 is the most widely used precipitation hardening nickel superalloy. Its unique niobium precipitate strengthening mechanism delivers superior high-temperature creep resistance unmatched by Inconel 625 solid solution alloy. Solid shaft serves high-load solid spindles, while seamless hollow shaft greatly reduces solid bar deep boring workload for tubular rotary parts. Widely processed into aircraft engine turbine shafts, subsea rotary valve stems, nuclear reactor control spindles, sour oilfield downhole shafts and high-temperature furnace roller blanks for aerospace, offshore energy, nuclear power and petrochemical industries.
Material Grade Characteristics – Inconel 718 (UNS N07718 / 2.4668)
- Ni-Cr-Fe alloy strengthened by γ'' niobium precipitates via double aging heat treatment
- Maintain stable creep strength under long-term service below 704°C, ideal high-temperature rotating components
- Comprehensive anti-corrosion performance against brine, sour gas, hot alkali & organic acids, NACE compliant
- Excellent impact toughness at ultra-low cryogenic temperatures, no ductile-brittle transition
- Good weldability without post-weld cracking risk; aging can be carried out after welding
- Soft solution annealed condition supports all CNC turning, boring and complex machining processes
Chemical Composition (Weight %)
| Grade |
EN No. |
C ≤ |
Si ≤ |
Mn ≤ |
P ≤ |
S ≤ |
Cr |
Ni Min |
Mo |
Nb+Ta |
Ti |
Al |
Fe |
| Inconel 718 |
2.4668 |
0.08 |
0.35 |
0.35 |
0.015 |
0.015 |
17.0–21.0 |
50.0 |
2.8–3.3 |
4.75–5.50 |
0.65–1.15 |
0.20–0.80 |
Balance |
Mechanical Properties (ASTM B637 Standard States)
| Delivery State |
Min Tensile MPa |
Min Yield MPa |
Min Elongation % |
Hardness HB Reference |
| Condition A (Solution Annealed) |
965 |
550 |
30 |
≤240 HB |
| H925 Double Aged Standard |
1240 |
1030 |
12 |
340–390 HB |
| H1045 High Tough Aged |
1100 |
860 |
18 |
300–350 HB |
Unified Base Delivery Standard: Hot Rolled / Cold Drawn & Pierced, Solution Annealed (Condition A), Stress‑Relieved, Pickled
Related Material Grades
- Inconel Series: 600, 601, 625, 690, 718, X-750, HX
- Incoloy Series: 800, 800H, 800HT, 825, 925
- 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 High-Temperature Creep Resistance
Double aging delivers sustained high tensile & creep strength up to 704°C, far superior to solid-solution nickel alloys for long-cycle hot rotating equipment.
2 Sour Gas & Seawater Corrosion Proof
Pass NACE MR0175 standard, fully resist sulfide stress cracking, suitable for offshore subsea & H₂S oil well shaft parts.
3 Wide Temperature Toughness Range
Maintain excellent ductility from cryogenic to medium high temperature, no brittle failure risk under alternating cold-hot working conditions.
4 Dual Solid/Hollow Stock Supply
Seamless hollow shaft avoids deep boring on solid bar, greatly reduces raw material waste and CNC processing time for tubular spindles.
5 Stable Welding & Aging Performance
No welding hot cracking; aging heat treatment can be performed after full assembly of welded shaft components.
Typical Applications
- Aerospace: Aircraft turbine main shafts, engine rotary spindles, landing gear high-strength pins
- Offshore Oil & Gas: Subsea wellhead valve stems, sour gas downhole pump shafts
- Nuclear Power: Reactor control shafts, heat exchanger rotary supporting rods
- High-Temp Furnace: Heat treatment furnace roller shafts, high-temperature agitator spindles
- Chemical Equipment: High-pressure reactor stirring shafts, hot alkali medium rotary parts
- General Heavy Machinery: High-load gear shafts, precision high-temperature bearing mandrels
Processing Service
We provide integrated hot rolling & seamless piercing hollow shaft production, full custom CNC machining per customer CAD/PDF drawings:
- Fixed-length cutting, centering, OD turning, hollow internal boring, chamfering
- Precision threading, spline machining, cylindrical grinding & mirror polishing
- Custom H925 / H1045 double aging heat treatment service
- Pickling, passivation anti-corrosion surface finishing
We supply Inconel 718 solid & hollow shaft blanks plus fully machined finished spindles for aerospace, offshore, nuclear and chemical global industrial clients.
Quality Assurance
- 100% UT + Eddy Current dual inspection to detect rolling/piercing internal defects
- Full batch tensile, yield, elongation & hardness mechanical testing for each heat lot
- High-precision micrometer & CMM to control diameter, wall thickness & straightness tolerance
- Spectrometer full-spectrum chemical composition verification per heat number
- Metallographic γ'' precipitate microstructure inspection after aging 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 protection
- Outer: Reinforced fumigated wooden pallet with separation strips to prevent scratch & bending deformation
- 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 requirements.
