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Data Sheets

Nickel Alloy

Alloy 625

Alloy 625 is a Nickel-Chromium based alloy with Min 58% Nickel which gains its stiffening effect through additions of Molybdenum and Niobium thus eliminating the need for this alloy to be aged.
It has superior resistance to a wide range of corrosive environments as well as the high temperature effects of oxidation and carburisation.
Alloy 625 is excellent for sea-water applications, having freedom from pitting and crevice corrosion, high fatigue strength and resistance to chloride-ion stress corrosion cracking.

Chemical Composition

ASTM B446-03 (2014)
Alloy 625
Chemical Element % Present
Chromium (Cr) 20.00 - 23.00
Molybdenum (Mo) 8.00 - 10.00
Aluminium (Al) 0.0 - 0.40
Carbon (C) 0.0 - 0.10
Cobalt (Co) 0.0 - 1.00
Columbium + Tantalum (Cb+Ta) 3.15 - 4.15
Iron (Fe) 0.0 - 5.00
Manganese (Mn) 0.0 - 0.50
Phosphorous (P) 0.0 - 0.02
Silicon (Si) 0.0 - 0.50
Sulphur (S) 0.0 - 0.02
Titanium (Ti) 0.0 - 0.40
Nickel (Ni) Balance

Alloy Designations

ASTM B446-03 (2014) UNS N06625,

NACE MR0175 / ISO 15156-3

Generic Physical Properties

Physical Property Value
Density 8.47 g/cm³
Melting Point 1290-1350 °C
Modulus of Elasticity 209 GPa
Room temperature Physical Properties are shown (20C) and most vary as temperature changes.

Mechanical Properties

ASTM B446-03 (2014) UNS N06625 Grade 1
Hot Worked Rod & Bar, Annealed - Up to 4in (102mm) incl.
Mechanical Property Value
Proof Stress 415 Min MPa
Tensile Strength 830 Min MPa
Elongation A50 mm 30 Min %
ASTM B446-03 (2014) UNS N06625 Grade 1
Hot Worked Rod & Bar, Annealed - Over 4in (102mm) - 10 in (254mm)
Mechanical Property Value
Proof Stress 345 Min MPa
Tensile Strength 760 Min MPa
Elongation A50 mm 25 Min %


Equipment for production of phosphoric acid

Radioactive waste treatment plants

Oil production pipe systems and riser linings

Offshore industry and seawater exposed equipment

Sea-water piping in shipbuilding

Stress corrosion cracking resistant compensators

Furnace linings

Components in oil and gas extraction


Exceptional resistance to pitting, crevice corrosion, erosion and intergranular corosion

Immunity to chloride-induced stress corrosion cracking

Good resistance to mineral acids such as nitric, phosphoric, sulfuric, and hydrochloric acids

Good resistance to alkalis and organic acids

Good mechanical properties

Excellent weldability

Low magnetic permeability


This Data is indicative only and as such is not to be relied upon in place of the full specification. In particular, mechanical property requirements vary widely with temper, product and product dimensions. All information is based on our present knowledge and is given in good faith. No liability will be accepted by the Company in respect of any action taken by any third party in reliance thereon.

Please note that the 'Datasheet Update' date shown above is no guarantee of accuracy or whether the datasheet is up to date.

The information provided in this datasheet has been drawn from various recognised sources, including EN Standards, recognised industry references (printed & online) and manufacturers’ data. No guarantee is given that the information is from the latest issue of those sources or about the accuracy of those sources.

Material supplied by the Company may vary significantly from this data, but will conform to all relevant and applicable standards.

As the products detailed may be used for a wide variety of purposes and as the Company has no control over their use; the Company specifically excludes all conditions or warranties expressed or implied by statute or otherwise as to dimensions, properties and/or fitness for any particular purpose, whether expressed or implied.

Advice given by the Company to any third party is given for that party’s assistance only and without liability on the part of the Company. All transactions are subject to the Company’s current Conditions of Sale. The extent of the Company’s liabilities to any customer is clearly set out in those Conditions; a copy of which is available on request.