Alloy 625 - AMS 5599, AMS 5666, UNS N06625

Inconel® 625 (AMS 5599, UNS N06625) is a nickel-based superalloy with excellent resistance to oxidation and corrosion. The nickel-chromium matrix of this material is reinforced by the addition of molybdenum and niobium, which is alloyed through solid solution strengthening. This process allows alloy 625 to maintain high strength and toughness at temperatures ranging from cryogenic up to 1800°F (982°C). It is non-magnetic, austenitic, and displays high tensile strength, fabricability, and brazeability. Due to its high nickel content, this alloy is nearly immune to chloride ion stress-corrosion cracking and pitting, which is commonly found in thin-walled seawater applications like heat exchangers, fasteners, and cable sheathing. We sell alloy 625 materials in sheet, coil, plate and round bar.


625 Inventory Size Ranges

Sheet & Coil

0.016" - 0.130"

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Plate

0.1875" - 2.000"

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Bar

0.375" - 7.000"

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Characteristics of Inconel 625

  • High strength and mechanical properties at both cryogenic and high temperatures.
  • High oxidation resistance at temperatures up to 1050°C.
  • High tensile, creep, and rupture strength.
  • Good resistance to oxidizing and reducing acids such as nitric, sulfuric, hydrochloric and phosphoric acid.
  • Virtually immune to chloride ion stress-corrosion cracking and pitting, making it ideal for marine applications.
  • Excellent weldabilty

Working with Inconel 625

Alloy 625 can be cold formed, hot worked, and machined through most standard methods. Hot forming should be done at temperature ranges of 1700 – 2150°F (927-1177°C), and care should be taken when cold working and machining, as it work hardens more quickly than more traditional austenitic stainless steels. Recommend using rigid, powerful machines with sharp tooling at positive rake angles, with tools changed frequently to maintain sharpness. Heavy constant feeds are advised to maintain a positive cutting action with proper lubrication. All 625 may be welded through typical gas shielded processes.

Heat treatment of Inconel 625

This alloy has three primary heat treatments – solution annealing at 2000-2200°F (1093 – 1204°C) with air or rapid quenching, annealing at 1600-1900°F (927-1038°C) with air or rapid quenching, and stress relieving at 1100-1600°F(593 – 900°C) with air quenching. Each process results in different characteristics, with the high temperature annealing used for applications above 1500°F where creep resistance is important. The medium temperature annealing provides optimal tensile and rupture properties up to 1900°F (1038°C), while the stress relieved state is recommended for applications under 1200°F (649°C), where maximum fatigue, hardness and yield strength are required.


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Standard Inventory Specifications

625 Sheet, Coil and Plate:

  • UNS N06625
  • UNS N06626-625LCF
  • AMS 5599
  • ASTM B 443 Gr 1
  • ASME SB 443 Gr 1

625 Bar:

  • UNS N06625
  • UNS N06626-625LCF
  • AMS 5666
  • ASTM B 446

Other industry standards we comply with:

  • EMS95377
  • EN 2.4856
  • EN 10204
  • DFARS Compliant
  • RR SABRe Edition 2
  • GE Aircraft Engine (GT193)
  • GE Aviation S-SPEC-35 AeDMS S-400
  • PWA LCS

Common Trade Names

  • Alloy 625
  • Nickel 625
  • Inconel 625 (® Special Metals)
  • Haynes 625 (® Haynes International)

Common Applications of 625

  • Aerospace components
  • Fasteners
  • Chemical Processing
  • Propeller blades
  • Submarine propulsion motors
  • Utility boat exhaust ducts
  • Steam-line bellows
  • Heat Exchangers
  • Flue gas desulfurization scrubbers
  • Chemical processing equipment for oxidizing and reducing acids
  • Marine components exposed to seawater, such as fasteners and cable connectors
Chemical Composition of Inconel 625
Element Percent by Weight
C Carbon 0.010 maximum
Mn Manganese 0.50 maximum
P Phosphorus 0.015 maximum
S Sulfur 0.015 maximum
Si Silicon 0.50 maximum
Cr Chromium 20.00 - 23.00
Ni Nickel Balance
Mo Molybdenum 8.00 - 10.00
Nb Columbium 3.15 - 4.15
Ti Titanium 0.40 maximum
Al Aluminum 0.40 maximum
Ta Tantalum 0.05 maximum
Fe Iron 5.00 maximum

Physical Properties

  • Density: 0.303 lb/in3 (8.44 g/cm3
  • Specific Gravity: 8.44
  • Melting Range: 2350 - 2460°F (1280 - 1350°C)
  • Specific Heat: 0.098 Btu/lb x °F (410 Joules/kg x °K)
  • Magnetic Permeability (75°F, 200 oersted): 1.0006

Thermal Conductivity

Temperature Range Linear Coefficients of Thermal Expansion1 · 10-6 Thermal Conductivity2 3
°C °F /°C /°F W/m·K Btu/(hr/ft²/in/°F)
-157 -250 - - 7.3 4.2
-129 -200 - - 7.4 4.3
-73 -100 - - 8.3 4.8
-18 0 - - 9.2 5.3
21 70 - - 9.9 5.7
38 100 - - 10.0 5.8
93 200 12.8 7.1 10.7 6.3
204 400 13.1 7.3 12.6 7.3
316 600 13.3 7.4 14.2 8.2
427 800 13.7 7.6 15.7 9.1
538 1000 14.0 7.8 17.5 10.1
649 1200 14.8 8.2 19.0 11.0
760 1400 15.3 8.5 20.8 12.0
871 1600 15.8 8.8 22.8 13.2
927 1700 16.2 9.0 - -
982 1800 - - 25.3 14.6
  1. Average coefficient from 70°F (21°C) to temperature shown
  2. Measurements made at Battelle Memorial Institute
  3. Material annealed 2100°F (1149°C)

Electrical Resistivity

Temperature microhm-cm
°C °F
21 70 128.9
38 100 129.6
93 200 131.9
204 400 133.9
316 600 134.9
427 800 135.9
538 1000 137.9
649 1200 137.9
760 1400 136.9
871 1600 135.9
982 1800 134.9
1093 2000 133.9

Mechanical Properties and Yield Strength

Mechanical Properties and Yield Strength of Alloy 625

Temperature 0.2% Yield Strength Ultimate Tensile Strength Elongation Percent
°F °C psi MPa psi MPa
1920 1065 63,000 430 136,000 940 51.5

The technical data provided is for information only and not for design purposes. It is not warranted or guaranteed.


Please contact us for more details. The technical data provided is for information only and not for design purposes. It is not warranted or guaranteed.