What is the chemical composition of Inconel 625?

UNS N06625 / W.Nr. 2.4856: nickel balance, 20-23% chromium, 8-10% molybdenum and 3.15-4.15% niobium plus tantalum.

How does 625 get its strength without heat treatment?

The niobium and molybdenum stiffen the solid-solution matrix, giving high strength in the annealed condition.

What are its mechanical properties?

Tensile about 930 MPa (135 ksi), yield about 517 MPa (75 ksi) and 42.5% elongation.

What are typical applications?

Aerospace ducting, chemical processing, marine engineering and nuclear components.

What standards cover 625?

UNS N06625 / W.Nr. 2.4856, with ASTM B446 and AMS 5666 covering bar and shapes.

Is Inconel 625 weldable?

Yes - it is one of the most weldable nickel alloys, with the niobium preventing sensitization.

Round bar, plate, sheet, tube, pipe, wire, forgings and welding filler.

It resists a wide range of severely corrosive environments and is especially resistant to pitting and crevice corrosion.

Inconel is a registered family of nickel-chromium-based superalloys characterised by high strength and oxidation resistance at elevated temperature.

Which Inconel grade should I choose for high temperature?

Inconel 601 for oxidation up to about 1250 C, Inconel 617 and 625 for creep-limited service, and Inconel 718 where high tensile and fatigue strength up to about 650 C is required.

Which Inconel is best for sour gas (H2S) service?

Age-hardenable grades Inconel 718 and Inconel 725 are the standard choices for sour-gas downhole tubing and wellhead components under NACE MR0175 / ISO 15156.

Most Inconel grades are fully austenitic and non-magnetic in the annealed condition; cold work can produce slight magnetism in some grades.

Can Inconel be welded?

Yes. Most grades are welded with matching or over-alloyed nickel filler metals under AWS A5.14 (for example ERNiCrMo-3 for 625, ERNiCr-3 for 600/601, ERNiFeCr-2 for 718).

Nickel Alloy Grade Cross-Reference: UNS, W.Nr. and AMS

Quick Answer

How do I cross-reference a nickel alloy between UNS, W.Nr. and AMS?

Most nickel grades carry three parallel designations: a UNS number (for example N06625 for Inconel 625), a German Werkstoffnummer (W.Nr. 2.4856) and one or more SAE AMS aerospace specifications (AMS 5599). The table below lists all three where published.

What are the three designation systems?

UNS (Unified Numbering System) — the North American materials identifier; nickel alloys use the N-prefix series (N06xxx, N07xxx, N08xxx) while copper-nickel uses the C-series.
W.Nr. (Werkstoffnummer / DIN) — the German material number; nickel alloys typically fall in the 2.4xxx series.
AMS (Aerospace Material Specification, SAE International) — aerospace procurement specifications that additionally define melting practice, heat treatment and testing requirements.

Equivalence between systems is nominal: two specifications may differ slightly in composition limits, heat treatment or required testing. Always confirm against the current revision of the specification you are purchasing to.

Grade cross-reference table

Grade	UNS	W.Nr. (DIN)	Typical AMS
Inconel 600	N06600	2.4816	AMS 5540
Inconel 601	N06601	2.4851	AMS 5715
Inconel 617	N06617	2.4663	AMS 5887
Inconel 625	N06625	2.4856	AMS 5599
Inconel 686	N06686	2.4606	—
Inconel 690	N06690	2.4642	AMS 5599
Inconel 693	N06693	—	—
Inconel 706	N09706	—	AMS 5701
Inconel 713C	N07713	2.4671	AMS 5377
Inconel 718	N07718	2.4668	AMS 5662
Inconel 725	N07725	—	AMS 5580
Inconel 740H	N07740	—	AMS 5744
Inconel 751	N07751	—	—
Inconel 783	N07783	—	AMS 5940
Inconel X-750	N07750	2.4669	AMS 5667
Hastelloy B-2	N10665	2.4617	—
Hastelloy B-3	N10675	2.4600	—
Hastelloy C-4	N06455	2.4610	—
Hastelloy C-22	N06022	2.4602	AMS 5750
Hastelloy C-276	N10276	2.4819	AMS 5750
Hastelloy C-2000	N06200	2.4675	—
Hastelloy G-30	N06030	2.4603	—
Hastelloy G-35	N06035	2.4643	—
Hastelloy N	N10003	—	—
Hastelloy X	N06002	2.4665	AMS 5536
Monel 400	N04400	2.4360	AMS 4544
Monel R-405	N04405	2.4361	—
Monel K-500	N05500	2.4375	AMS 4676
Incoloy 800	N08800	1.4876	—
Incoloy 800H	N08810	1.4958	AMS 5766
Incoloy 800HT	N08811	1.4959	—
Incoloy 825	N08825	2.4858	—
Incoloy 925	N09925	—	—
Incoloy 890	N08890	—	—
Nickel 200	N02200	2.4066	—
Nickel 201	N02201	2.4068	—
Alloy 20	N08020	2.4660	—
Alloy 31	N08031	1.4562	—
Alloy 59	N06059	2.4605	—
Copper-Nickel 90/10	C70600	2.0872	—
Copper-Nickel 70/30	C71500	2.0882	—
Inconel 738LC	N07738	—	AMS 5410

How should I specify an alloy on a purchase order?

State the grade name, the UNS number, the governing specification (for example ASTM B443 for Inconel 625 plate, ASTM B446 for bar), the product form and dimensions, the required condition or heat treatment, and the certification level (EN 10204 3.1 or 3.2). Where an AMS specification applies, quote the revision letter.

Need help identifying an unknown grade?

Send us the marking, a spectrographic analysis or the original specification and we will identify the equivalent grade and available stock. WhatsApp +86 13611656360 or email hangbo@nickel-alloy.com.

Related references

Alloy family index · Knowledge Center · Product range by grade · Certifications

Nickel Alloy Grade Cross-Reference

What are the three designation systems?

Grade cross-reference table

How should I specify an alloy on a purchase order?

Need help identifying an unknown grade?

Related references

Related Alloy Knowledge