Inconel 718 Strip & Coil with Standard Tolerance

In the production of aerospace bellows, flexible seals, diaphragm assemblies, and edge-welded metal hose, flat-rolled Inconel 718 (UNS N07718 / W.Nr. 2.4668 / GH4169)​ must exhibit not only certified precipitation-hardening chemistry but also tight thickness uniformity, minimal camber, and a clean, oxide-free surface to prevent weld defects. Shanghai COCESS Special Alloys Co., Ltd​ supplies Inconel 718 strip and coil in the solution-annealed condition per ASTM B670 and AMS 5597, offered in standard dimensional tolerances suitable for deep drawing, photo-chemical milling, and precision stamping, with full EN 10204 3.1 documentation and optional third-party inspection.

Metallurgical Background & Chemical Composition

Inconel 718 is a precipitation-hardenable Ni-Cr-Fe alloy strengthened by coherent γ" (Ni₃Nb) precipitates during a two-step aging cycle (720°C × 8h + furnace cool to 620°C × 8h). Strip and coil are supplied in the solution-annealed (soft) condition​ to permit cold forming; final strength is developed by the end-user after forming and welding.

Typical Chemistry (wt%, per AMS 5597 / ASTM B670):

• Nickel (Ni):​ 50.00 – 55.00 % (Balance)

• Chromium (Cr):​ 17.00 – 21.00 % (Oxidation resistance)

• Iron (Fe):​ 16.00 – 20.00 % (Austenite stabilizer)

• Niobium + Tantalum (Nb+Ta):​ 4.75 – 5.50 % (Primary γ" (Ni₃Nb) strengthener)

• Molybdenum (Mo):​ 2.80 – 3.30 % (Solid-solution strengthening, pitting resistance)

• Titanium (Ti):​ 0.65 – 1.15 %

• Aluminum (Al):​ 0.20 – 0.80 %

• Carbon (C):​ ≤ 0.08 %

• Sulfur (S):​ ≤ 0.015 % (Tightly controlled for surface & hot workability)

• Boron (B):​ ≤ 0.006 %

• Cobalt (Co):​ ≤ 1.00 %

Mechanical Properties (Solution Treated + Aged per AMS 5663)

Material is sold soft for fabrication and designed to reach the following after customer-side aging:

• Tensile Strength (Rm):​ ≥ 1275 MPa (185 ksi); typical 1300–1380 MPa

• Yield Strength (Rp0.2):​ ≥ 1035 MPa (150 ksi); typical 1100–1170 MPa

• Elongation (A5):​ ≥ 12–15 % (higher in thin-gauge strip)

• Hardness:​ 331–401 HB (34–44 HRC) in fully aged condition

• Density:​ 8.24 g/cm³

• Service Temp:​ –253 °C to 650 °C continuous

Strip & Coil Supply Range — Standard Tolerances

We stock and produce Inconel 718 strip and coil in the following typical range. Custom widths, oscillate-wound coil, and tighter-than-standard tolerance are available upon request.

Standard Dimensional Tolerances (typical, per ASTM B670 / AMS 5597 reference):

• Thickness Tolerance:​ ± 0.010 mm for t ≤ 0.50 mm; ± 0.015–0.025 mm for 0.50–3.00 mm (can be tightened to ±0.005 mm on request).

• Width Tolerance:​ ± 0.10 mm to ± 0.25 mm depending on width.

• Camber:​ ≤ 1 mm per 1000 mm length (typical for BA strip).

• Edge Condition:​ Mill edge standard; slit/deburred edge available.

• Cast & Crown:​ Controlled to minimize spring-back variation in progressive die stamping.

Typical Applications for Inconel 718 Strip & Coil

• Aerospace & Space:​ Edge-welded bellows, diaphragm packs, pressure sensor capsules, seal laminae, and cryogenic (LOX/LH₂) instrument flex joints.

• Precision Engineering:​ Spring elements in high-temp environments, stamped clips / retainers for turbine assemblies.

• High-Performance Automotive / Racing:​ Thin-gauge heat shields, exhaust gas recirculation (EGR) diaphragms.

• Electronics / Instrumentation:​ High-reliability spring contacts in harsh (corrosive + warm) environments where 300-series SS would creep relax.

Quality Assurance & Value-Added Options

Every shipment from Shanghai COCESS Special Alloys Co., Ltd​ includes:

• EN 10204 3.1 Mill Test Report:​ Heat analysis, mechanical test results, and heat treatment record.

• Dimensional Inspection:​ Thickness measured at multiple points across coil width/length; width and camber verified.

• Surface Quality Check:​ Freedom from scratches, roll marks, and oxide scale that could initiate cracks in formed bellows or welded seams.

• Optional Services:

  • Tighter thickness tolerance (e.g., ±0.005 mm)

  • Oscillate-wound (ribbon) coil for automatic stamping lines

  • Interleaved flat-cut strips for blanking

  • Special decoiled flatness certification

  • Third-party witness (SGS, TÜV, DNV, etc.)

For current Inconel 718 strip and coil stock — including available thickness/width combinations, sample MTR, or a project quotation — please contact Shanghai COCESS Special Alloys Co., Ltd. Our technical staff can advise on minimum bend radius, forming allowance, and post-form aging practices to help ensure defect-free stamped or hydroformed parts from our material.

Website: https://en.cocessalloys.com
Email: sales@cocessalloys.com