Alloy 625 - UNS N06625

Alloy 625, UNS N06625, is commonly associated with ASTM B443 - ASTM B444 - ASTM B446 - AMS 5666 - AMS 5599.
Alloy 625 is commonly known as Inconel® 625 and is commercially available in grade 1 though HPA also has some stock in grade 2 and Low Cycle Fatigue (LCF). Alloy 625 is a Nickel-Chrome alloy.
Mechanical properties here.


C Cr Fe Mo Mn Ni Si
Max 0.1% 23% 5% 10% 0.5% 0.5%
Min 20% 8% 58%

Typical Inventory

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

Product Description

Nickel-chromium-molybdenum alloy 625 is a material with excellent resistance to pitting, crevice and corrosion cracking.

Highly resistant in a wide range of organic and mineral acids.

Good high temperature strength.

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.


  • 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.

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.

Ultimate Tensile (ksi) Yield Strength (ksi) Elong. % in 2 in. Reduction of Area Hardness (Rockwell C)
Min 120 60 30 40 145
Max 150 95 60 60 220

Common Specifications

Please, note that the specs listed are for reference and are not comprehensive nor indicative of the actual specifications listed on the Material Test Report (MTR). If you have a special spec requirement, then please reach out to our sales department at 1-800-472-5569.

Form Standard
Metal Type UNS N06625
Bar ASTM B446, AMS 5666, BS3076
Wire AMS 5837
Sheet ASTM B443, AMS 5599, BS3072
Plate ASTM B443, AMS 5599, BS3072
Pipe ASTM B444, BS3074, GEB50TF133
Tube ASTM B444, ASTM B704, AMS 5581, BS3074, GEB50TF133
Fitting ASTM B366, DIN 17754
NA 21 All forms
Din 2.4856

Plasma Arc Cutting

Our alloys can be cut using any conventional plasma arc cutting system. The best arc quality is achieved using a mixture of argon and hydrogen gases. Nitrogen gas can be substituted for hydrogen gases, but the cut quality will deteriorate slightly. Shop air or any oxygen bearing gases should be avoided when plasma cutting these alloys.


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.

Data Sheet

Download our datasheet here

Ulbrich's information on alloy 625

Link back to top of page
Link back to all alloys