A common trait the Inconel 625 Tube shares with its fellow nickel alloy are its ability to perform well in elevated temperatures. However, the main reason why many industries choose to use the 625 Inconel welded tube is that the alloy can offer much better resistance to crevice corrosion.



Therefore the marine industry, in particular, prefers to use the UNS N06625 Tubing for its engineering applications. Furthermore, the Nickel Alloy 625 Annealed Tube not only demonstrates superb creep rupture strength, but it also exhibits excellent resistance to fatigue. In addition to these unique properties, the alloy also exhibits excellent chloride pitting resistance. Inconel 625 tubes are covered by 2 specifications on the basis of their construction i.e. ASTM B516 which covers welded constructed pipes and the ASTM B163 which covers seamless constructed pipes.
Both the specifications cover the chemical analysis and mechanical parameters of the ASTM B163 Alloy 625 Seamless Tubing. In addition, the DIN 2.4856 cold drawn tube produced under these specifications are designed to be used for high temperature services. Hence both the ASME SB163 625 as well as tubes produced in accordance with the ASTM B516 specification find use in combination with boilers along with heat exchanger and condenser.
ASTM B516 Inconel 625 hot finish tubing produced under this specification is to undergo a flattening test. The flattening test performed on the specimen in order to check for superficial ruptures which could result from surface imperfections. In addition to the flattening test a flange test, along with any one nondestructive tests i.e. either hydrostatic or pneumatic tests are performed for leak testing. While an eddy current or ultrasonic test is to be conducted on the Alloy 625 Seamless Tubing for electric testing.
Specifications | ASTM B163, B516 / ASME SB163, B516 |
Dimensions | ASTM, ASME and API |
Alloy 625 Tubes Size |
6 mm OD x 0.7 mm to 50.8 mm OD x 3 mm thk. |
Schedule | STD, SCH80, XXS, XS, SCH20, SCH140, SCH30, SCH160, SCH60, SCH80, SCH120, SCH40 |
Type | ERW / Seamless/ Fabricated /LSAW /Welded Tubes |
Form | Rectangular, Round, Square, Hydraulic etc |
Length | Single Random, Double Random & Cut Length. |
End | Beveled End, Plain End, Threaded |
Alloy 625 tube
6 mm OD x 0.7 mm to 50.8 mm OD x 3 mm thk.
Grade | C | Mn | Si | S | Cu | Fe | Ni | Cr |
625 | 0.10max | 0.50 max | 0.50 max | 0.015max | – | 5.0 max | 58.0 min | 20.0 – 23.0 |
STANDARD | WNR Material Number | JIS | EN | BS | UNS | AFNOR | GOST |
625 | 2.4856 | NCF 625 | NiCr22Mo9Nb | NA 21 | N06625 | NC22DNB4M | ХН75МБТЮ |
Element | Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation |
625 | 8.4 g/cm3 | 1350 °C (2460 °F) | Psi – 1,35,000 , MPa – 930 | Psi – 75,000 , MPa – 517 | 42.5 % |
The alloy 625 material composes of nickel, chromium, molybdenum, niobium, cobalt, manganese, aluminum, titanium, silicon, carbon, sulfur and phosphorus. This combination gives the material excellent ductility and resistant to scaling even at elevated temperatures. Due to these properties this material can be formed in to smaller tubes. They can go down to 0.01 inches in wall thickness and 1/6 inches in outer diameter. Due to the ability of the material to be scaled down to smaller sizes, it is suitable for capillary tubing. So most capillary tubes are made in this material and are called the Inconel 625 capillary tubing.

ASTM B444 Gr.2 Alloy 625 Seamless U Bend Tube

nickel alloy 625 tubing

inconel NCF 625 material

WERKSTOFF NR. 2.4856 annealed tube

ASME SB163 625 Alloy hot finish tubing

ASTM B516 Alloy 625 welded tube

ASME SB516 Alloy 625 Erw Tubing

ASTM B163 Alloy 625 cold drawn tube