Inconel® 625

Inconel® 625 - UNS N06625 - W. Nr. 2.4856 - Nickel Alloy 625 - NiCr Alloy

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Table of Contents
Datasheet Chemistry
Inventory Applications
General Data Mechanical Properties
Specifications Machining, Welding, & Processing

Nickel-chromium-molybdenum alloy 625 is a material with excellent resistance to pitting, crevice, and corrosion cracking. This alloy is highly resistant in a wide range of organic and mineral acids, and it exhibits good high temperature strength.


View or download our 625 datasheet here


Min% Max%
Ni 58.0
Cr 20.0 23.0
Fe 5.0
Mo 8.0 10.0
Nb (+Ta) 3.15 4.15
C 0.10
Mn 0.50
Si 0.50
P 0.015
S 0.015
Al 0.40
Ti 0.40
Co 1.0
*Composition information provided by Special Metals' datasheet on Inconel® 625, available here.

Typical Inventory

Round Bar, Plate, Tubing, Pipe, Fastener, Forge, Billet


  • Components where exposure to sea water and high mechanical stresses are required.
  • Oil and gas production where hydrogen sulfide and elementary sulfur exist at temperature in excess of 150 °C.
  • Components exposed to flue gas or in flue gas desulfurization plants.
  • Flare stacks on offshore oil platforms.
  • Hydrocarbon processing from tar-sand and oil-shale recovery projects.

General Data

  • Excellent mechanical properties at both extremely low and extremely high temperatures.
  • Outstanding resistance to pitting, crevice corrosion, and intercrystalline corrosion.
  • Almost complete freedom from chloride induced stress corrosion cracking.
  • High resistance to oxidation at elevated temperatures up to 1050 °C.
  • Good resistance to acids, such as nitric, phosphoric, sulfuric, and hydrochloric, as well as to alkalis makes possible the construction of thin structural parts of high heat transfer.

Mechanical Properties

The typical properties listed can usually be provided in rounds, sheet, strip, plate, & custom forgings. We have the equipment to produce small quantities in special sizes to meet our customers’ specific needs. The table below shows Special Metals' Nominal Room-Temperature Mechanical Properties of Alloy 625 Rod, Bar, and Plate. For most common forms and exceptions, check out the datasheet linked underneath the table.

Form Cond. UTS ksi (MPa) YS ksi (MPa) Elong., % Reduction of Area, % Brinell Hardness
Rod, Bar, Plate As-Rolled 120-160 (827-1103) 60-110 (414-758) 60-30 60-40 175-240
Rod, Bar, Plate Anneal 120-150 (827-1034) 60-95 (414-655) 60-30 60-40 145-220
Rod, Bar, Plate Sol. Tr. 105-130 (724-896) 42-60 (290-414) 65-40 90-60 116-194

UTS = Ultimate Tensile Strength, YS = Yield Strength, Sol. Tr. = Solution-Treated

Link to Special Metals' datasheet on Inconel® 625

Common Specifications

Note that the specifications listed are common for this alloy but are for reference only and may be specific to a certain form. The specifications listed are not comprehensive nor indicative of any edition, revision, or similar such as an amendment. Please, reach out to our sales department to request the Material Test Report (MTR) or to confirm your required specifications.

Form Standard
Identification UNS N06625, EN 10095, DIN 17744, DIN 17750 – 17754, W. Nr. 2.4856
Bar AMS 5666, ASTM B446, ASME SB446
Sheet, Plate, or Strip AMS 5599, ASTM B443, ASME SB443
Forging AMS 5666, ASTM B564, ASME SB564
Pipe - Seamless ASTM B444, ASTM B829, ASME SB444, ASME SB829
Pipe - Welded ASTM B705, ASTM B775, ASME SB705, ASME SB775
Tube - Seamless AMS 5581 Type 1, ASTM B444, ASTM B829, ASME SB444, ASME SB829
Tube - Welded AMS 5581 Type 2, ASTM B704, ASTM B751, ASME SB704, ASME SB751
Fitting ASTM B366, ASME SB366
Weld Wire Inconel® FM 625/ UNS N06625/ W. Nr. 2.4831/ AWS A5.14 ERNiCrMo-3/ ASME IX F-No. 43/ AMS 5837
Weld Electrode Inconel® WE 112/ UNS W86112/ W. Nr. 2.4621/ AWS A5.11 ENiCrMo-3/ ASME IX F-No. 43
Others NACE MR-0175, ISO 15156


Nickel and cobalt based alloys can be difficult to machinine. However, it should be emphasized that these alloys can be machined using conventional production methods at satisfactory rates. These alloys harden rapidly, generate high heat during cutting, weld to the cutting tool surface and offer high resistance to metal removal because of their high shear strengths. The following are key points which should be considered during machining operations:

  • CAPACITY - Machine should be rigid and overpowered as much as possible.
  • RIGIDITY - Work piece and tool should be held rigid. Minimize tool overhang.
  • TOOL SHARPNESS - Make sure tools are sharp at all times. Change to sharpened tools at regular intervals rather than out of necessity. A 0.015 inch wear land is considered a dull tool.
  • TOOLS - Use positive rake angle tools for most machining operations. Negative rake angle tools can be considered for intermittent cuts and heavy stock removal. Carbide-tipped tools are suggested for most applications. High speed tools can be used, with lower production rates, and are often recommended for intermittent cuts.
  • POSITIVE CUTS - Use heavy, constant, feeds to maintain positive cutting action. If feed slows and the tool dwells in the cut, work hardening occurs, tool life deteriorates and close tolerances are impossible.
  • LUBRICATION - lubricants are desirable. Soluble oils are recommended especially when using carbide tooling.


Link to Special Metals' datasheet on Inconel® 625

Inconel® is a registered trademark of the Special Metals Corporation group of companies.

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