Guide to Selecting Inconel Sheet, Strip, and Plate: A Comprehensive Analysis of Mainstream Grades, Standards, and Applications for 2026

Introduction

Comparison of 12 Major Inconel Alloy Grades and Standards (Sheet, Strip, and Plate Forms)

Before discussing suppliers, it is essential to clarify the alloy grades. A common pitfall in procurement is confusing Stellite 6 with Stellite 12; while they look similar, their performance characteristics and suitable applications differ vastly.

Alloy Grade	UNS	Primary Standard (Plate/Strip)	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation (%)	Core Positioning
Inconel 600 Plate / AMS 5540 / ASTM B168 Inconel 600	N06600	ASTM B168 / AMS 5540	≥550	≥240	≥30	A standard grade offering corrosion and heat resistance, as well as resistance to chloride-induced stress corrosion cracking (SCC); a classic material for the nuclear industry.
Inconel 601	N06601	ASTM B168 / AMS 5870	≥650	≥300	≥30	A benchmark for high-temperature oxidation resistance; contains 1.0–1.7% aluminum and withstands temperatures up to 1,200°C.
AMS 5889 / UNS N06617 / Inconel 617 Nickel Alloy Inconel 617	N06617	ASTM B168 / AMS 5888（sheet）/5889（strip）	≥810	≥410	≥54	Solid-solution strengthened superalloy featuring outstanding creep strength above 980°C; specifically designed for gas turbine combustion chambers.
AMS 5599 / Inconel 625 Nickel Alloy Sheet Inconel 625	N06625	ASTM B443 / AMS 5599 / AMS 5869	≥830	≥415	≥30	Corrosion-resistant and high-strength; resistant to seawater pitting; the preferred choice for marine, chemical, and flue-gas desulfurization applications.
Inconel 690 Inconel 690	N06690	ASTM B168 / ASME SB168	≥550	—	—	High-chromium (~30%), specifically for steam generator heat transfer tubes in nuclear power plants, resistant to stress corrosion.
Inconel 693	N06693	ASTM B168	—	—	—	High chromium + aluminum; suitable for extreme oxidation/carburization environments; offers superior corrosion resistance compared to 601.
AMS 5596 / Inconel 718 Plate, Sheet, and Strip Inconel 718	N07718	ASTM B670 / AMS 5596	≥1276	≥1034	≥12	Precipitation-hardening type; high strength at temperatures up to 700°C; a mainstay material for aero-engines and gas turbines.
Inconel 706 Inconel 706	N07706	AMS 5701	—	—	—	A variant of 718 with improved machinability, used for large forgings and rings.
AMS 5542 / Inconel X750 Plate, Sheet, and Strip Inconel X-750	N07750	ASTM B637 / AMS 5598（sheet/strip）	≥1173 after aging	≥747 after aging	≥30 after aging	Age-hardenable; high strength up to 871°C; suitable for springs, fasteners, and seal rings.
ASTM B127 / Inconel 725 Nickel Alloy Inconel 725	N07725	ASTM B805 / NACE MR0175	≥855（after aging）	≥427（after aging）	≥57	Age-hardened version of 625; strength doubled; designed specifically for acidic oil and gas wells.
Inconel 625 LCF	N06626	ASTM B443	≥830	—	—	Low-carbon version of 625, specifically designed for low-temperature fatigue resistance.
Inconel 740H	N07740	ASME Code Case 2702	—	—	—	Advanced ultra-supercritical boiler tubes/plates, designed for 620–760°C steam environments.

Data Notes:

The mechanical data in the table represent typical minimum values ​​or typical values.

• For Inconel 600, typical room-temperature properties are: tensile strength 655 MPa, yield strength 310 MPa, and elongation 45%.
• For annealed Inconel 601, minimum values ​​are: tensile strength 650 MPa, yield strength 300 MPa, and elongation 30%.
• For Inconel 625 cold-rolled sheet/strip (ASTM B443 Grade 1), minimum values ​​are: tensile strength 827 MPa, yield strength 414 MPa, and elongation 30%.
• For Inconel 617 solution-annealed sheet, typical values ​​are: tensile strength 810 MPa, yield strength 410 MPa, and elongation 54%.
• For Inconel 718 (per AMS 5662), room-temperature requirements are: yield strength ≥1034 MPa, tensile strength ≥1276 MPa, and elongation ≥12%.

Detailed Explanation of Standard Coverage

1. ASTM B168 (the latest version being B168-26) is the "master standard" for Inconel flat products, covering plate, sheet, and strip in the following UNS designations:

 - Nickel-chromium-aluminum alloys: N06699
 - Nickel-chromium-iron alloys: N06600, N06601, N06603, N06690, N06693, N06025, N06045, N06696
 - Nickel-chromium-cobalt-molybdenum alloys: N06617
 - Nickel-iron-chromium-tungsten alloys: N06674
 - Nickel-chromium-molybdenum-copper alloys: N06235
 

Note: Inconel 625 (N06625) and 718 (N07718) are not covered by ASTM B168. Plate and strip products for alloy 625 are covered by ASTM B443, while those for alloy 718 are covered by ASTM B670. Plate and strip products for Inconel X-750 are covered by ASTM B637.

The AMS series of standards primarily targets aerospace applications, imposing additional requirements regarding grain size and non-destructive testing:

AMS Standard	Covered Grades	Product Form	Key Additional Requirements
AMS 5540	Inconel 600	Sheet/Strip	Grain Size Control
AMS 5870	Inconel 601	Sheet/Strip	Supplied in solution-annealed condition
AMS 5888	Inconel 617	Plate	Ultrasonic testing
AMS 5889	Inconel 617	Strip	Grain size, surface quality
AMS 5599	Inconel 625	Sheet/Strip	Aviation-grade traceability
AMS 5869	Inconel 625	Sheet/Strip	High purity requirements
AMS 5596	Inconel 718	Sheet/Strip	Mechanical Acceptance Testing in the Aged State
AMS 5598	Inconel X-750	Sheet/Strip	Age-hardened state

Procurement Reminders and Common Pitfalls

Pitfall 1: Disputes arising from mixing AMS and ASTM standards
 

For the same alloy grade, AMS and ASTM standards may specify similar chemical compositions but differ in mechanical property requirements. For instance, the ASTM B166 standard for Inconel 601 bars requires a yield strength of ≥240 MPa, whereas the ASTM B168 standard for plates requires only ≥205 MPa. If you use the B166 criteria to inspect B168 plates, material that actually meets specifications could be wrongly rejected.

Pitfall 2: Applying plate specifications to strip material

ASTM B443 Grade 1 requires a yield strength of ≥414 MPa for Inconel 625 strip, while the requirement for hot-rolled medium-to-heavy plate (≤70 mm) may be as low as 379 MPa. Strip is strengthened through cold rolling and naturally possesses higher strength than hot-rolled plate. Problems arise if strip specifications are used to inspect plate, or vice versa.

Pitfall 3: Vague grain size requirements

ASTM B168 specifies clear grain size requirements for plates (typically ASTM No. 5 or coarser) to ensure high-temperature creep strength. However, many procurement orders omit this specification; suppliers deliver material that meets chemical composition requirements, yet the material fails to meet creep life standards at high temperatures.

Pitfall 4: Confusing AMS and ASTM versions of Inconel 617

AMS 5888 (plate) and AMS 5889 (strip) are aerospace-specific versions of Inconel 617, whereas ASTM B168 is the general industrial version. The AMS versions impose stricter limits on boron (≤0.006%) and titanium (≤0.60%) content. If the material is intended for use in an aero-engine combustion chamber, the AMS version must be specified.

Lork Purchasing Recommendations

1. First, determine the product form, then the applicable standard. For plate/sheet/strip, refer to ASTM B168 (for alloys 600, 601, 617, 690, 693), B443 (for 625), or B670 (for 718). Use B166 for bar stock and B167/B444 for tubing/pipe. The form and the standard must align.
2. The choice between AMS and ASTM depends on the end customer. Aerospace and defense projects require AMS specifications, whereas general industrial and petrochemical projects can utilize the ASTM B series.
3. Clearly specify grain size requirements in the purchase order. For high-temperature, pressure-bearing components, specify "Grain size per ASTM E112: Grade 5 or coarser."
4. Require the supplier to provide actual test data rather than just "standard values." This is particularly important for yield strength and grain size; standard values ​​represent only the minimum requirement, whereas actual test results reflect the quality of the specific batch.
5. For Inconel 725 used in oil and gas wells, NACE certification must be verified. Alloy 725 is an age-hardened version of Alloy 625 with double the strength; however, for applications in sour (acidic) environments, compliance with NACE MR0175 must be confirmed.