Acid Process Lines in Chemical Plants
Chemical plants run sulfuric, nitric and hydrochloric acid transfer piping in this alloy, together with acetic and phosphoric acid lines, where one material has to cover a changing mix of process streams.
ASTM B444 / ASME SB-444 / UNS N06625 / W.Nr. 2.4856
Inconel 625 Seamless Pipes Manufacturer in Thailand
Inconel 625 seamless pipes from Thaida Stainless Steel Manufacturing (Thailand) Co., Ltd. are cold worked to ASTM B444 / ASME SB-444 at our Ban Bueng, Chonburi mill and released in either of the two heat-treated grades the standard sets out. The material is UNS N06625, cross-referenced as W.Nr. 2.4856, and is listed with the other grades of our Inconel seamless pipes program. Our Bang Phli, Samut Prakan office handles line-class reviews, quotations and order documents.
Inconel 625 seamless pipeUNS N06625 / W.Nr. 2.4856
- 6 to 457 mmOutside diameter
- 1 to 35 mmWall thickness
- Up to 18 mLength
- EN 10204 3.1Test certificate
EN 10204 3.1 certificate / 3.2 on request
ASTM B444 Inconel 625 Seamless Pipes at a Glance
Each row below is a limit we hold on every order: the diameter, wall and length window of our mill, the two heat-treated grades, how a size is written on the order, and the tests reported on the certificate.
- Standard
- ASTM B444 / ASME SB-444
- Designation
- UNS N06625
- Grades
- Grade 1 (annealed) or Grade 2 (solution annealed)
- Grade 1 when the order names neither
- Outside Diameter
- 6 to 457 mm
- Wall Thickness
- 1 to 35 mm
- Length
- Up to 18 m
- Ordering Basis
- Standard pipe size and schedule
- Product Route
- 1Cold-worked seamless
- 2Then annealed or solution annealed to the grade ordered
- Finish
- Cold drawn and pickledor cold drawn with ground OD
- Ends
- Plaincut and deburred
- Testing
- Chemical analysis and tension test per lot
- Hydrostatic or nondestructive electric test on every length
- Test Certificate
- EN 10204 3.13.2 on request
ASTM B444, Standard Specification for Nickel-Chromium-Molybdenum-Niobium Alloys and Nickel-Chromium-Molybdenum-Silicon Alloy Pipe and Tube, scopes its product as cold-worked seamless pipe and tube, and ASME SB-444 is the matching specification for Boiler and Pressure Vessel Code work. UNS N06625 is the ASTM B444 / ASME SB-444 designation marked on the pipe and on the mill certificate, while Inconel 625 is the commercial name carried on the requisition. A pipe line item names the standard pipe size and the schedule, whereas Inconel 625 seamless tubes from the same standard are ordered by outside diameter with a nominal or minimum wall.
Chemistry is checked once per lot and a single tension specimen stands for the lot, while every length is proved hydrostatically or by nondestructive electric examination, at the mill's option unless your order names the method. B444 also lists a grain size test and two corrosion tests as supplementary requirements, added only when the purchase order calls for them. Results reach you on an EN 10204 3.1 (3.2 on request) material test certificate that states the heat number and the grade supplied, and third-party inspection is organized whenever your order asks for it.
UNS N06625 Seamless Pipe Chemical Composition
The heat analysis for UNS N06625 seamless pipe is checked against the ASTM B444 limits below, once per lot. Nickel carries a 58.0% minimum only and is found by difference once the other elements are measured. Iron is capped at 5.0%, and the 1.0% cobalt limit applies where cobalt is determined.
- NiNickel, 58.0 min
- CrChromium, 20.0 to 23.0
- MoMolybdenum, 8.0 to 10.0
- FeIron, 5.0 max
- NbNb (Niobium) + Ta (Tantalum), 3.15 to 4.15
UNS N06625625
| Element | Limit per ASTM B444 / ASME SB-444 (%) |
|---|---|
| Ni (Nickel) | 58.0 min |
| Cr (Chromium) | 20.0 to 23.0 |
| Mo (Molybdenum) | 8.0 to 10.0 |
| Nb (Niobium) + Ta (Tantalum) | 3.15 to 4.15 |
| Fe (Iron) | 5.0 max |
| Co (Cobalt), if determined | 1.0 max |
| C (Carbon) | 0.10 max |
| Mn (Manganese) | 0.50 max |
| Si (Silicon) | 0.50 max |
| P (Phosphorus) | 0.015 max |
| S (Sulfur) | 0.015 max |
| Al (Aluminum) | 0.40 max |
| Ti (Titanium) | 0.40 max |
Niobium and columbium are two names for one element, and ASTM B444 treats them as interchangeable. The 3.15 to 4.15% limit covers niobium and tantalum together, so a heat analysis reports their sum against it.
Grade 1 and Grade 2 Properties of ASME SB-444 625 Seamless Pipe
ASTM B444 furnishes this alloy in two grades of different heat-treated condition, and the grade decides both the mill anneal and the strength minimums each lot is tested against. Grade 1 is annealed and carries the higher minimums. Grade 2 is solution annealed and is the condition specified where creep and rupture resistance is required.
| Grade and Condition | Mill Heat Treatment | Tensile Strength, min, MPa (ksi) | Yield Strength (0.2% offset), min, MPa (ksi) | Elongation in 2 in. (50.8 mm) or 4D, min, % |
|---|---|---|---|---|
| Grade 1 (annealed) | Annealed at 871 °C (1600 °F) minimum | 827 (120) | 414 (60) | 30 |
| Grade 2 (solution annealed) | Solution annealed at 1093 °C (2000 °F) minimum, with or without a stabilization anneal at 982 °C (1800 °F) minimum | 690 (100) | 276 (40) | 30 |
Swipe sideways to see the full table.
When the purchase order names neither grade, Grade 1 is supplied, so a line class written for Grade 2 has to state it on every line item of an ASME SB-444 625 seamless pipe order. Both grades share the 30% elongation minimum, which leaves the decision to strength and to the creep and rupture requirement rather than to ductility.
Equivalent Designations of Inconel 625
Inconel 625 is written in the ways below on American, European and Japanese drawings. The product standard assigns the UNS number alone; the W.Nr. and JIS values are listed so that a drawing written in European or Japanese terms can be matched to it.
- Commercial nameInconel 625, also written Alloy 625
- ASTM B444 / ASME SB-444 (USA)UNS N06625
- Europe (W.Nr.)2.4856
- Japan (JIS)NCF625
When a drawing specifies 2.4856 or NCF625, we match it to N06625 at order entry, and the certificate carries the UNS number as the governing designation.
Seamless Alloy 2.4856 Pipe Sizes and Tolerances
Our seamless alloy 2.4856 pipe spans 6 to 457 mm in OD and 1 to 35 mm in wall, and the longest piece we deliver is 18 m. On the order, every item carries a nominal pipe size plus a schedule number, which sets the wall at that size inside the 1 to 35 mm window. ASTM B444 lists ground-OD pipe as normally supplied from 12.7 mm to 102 mm OD and pickled, unground pipe from 12.7 mm to 168 mm; finish on larger sizes is agreed at quotation.
Every length is cold-worked product, so the cold-worked tolerances that apply to ASTM B444 pipe govern it. Above 219 mm OD, the plus limit on diameter opens up while the minus limit holds at 0.79 mm:
| Nominal OD, in. (mm) | OD Plus, in. (mm) | OD Minus, in. (mm) | Nominal Wall, % | Minimum Wall, % |
|---|---|---|---|---|
| Over 8 5/8 (219) to 14 (356), incl | 0.062 (1.57) | 0.031 (0.79) | +15.0 / -12.5 | +30.0 / 0 |
| Over 14 (356) to 24 (610), incl | 0.125 (3.18) | 0.031 (0.79) | +15.0 / -12.5 | +30.0 / 0 |
Swipe sideways to see the full table.
Below 219 mm the bands narrow step by step as the diameter falls, and the quotation names the band for each size ordered. Single readings include ovality, with two exceptions, and the wall limits apply to single readings including eccentricity. Where the wall is 3% of the OD or less, the mean diameter meets the band and single readings may run a further 0.5% of the nominal OD beyond it. At these diameters, all above 114 mm, a wall heavier than 3% of the OD means the mean diameter meets the band while one reading may reach twice the tabulated figure. Our envelope ends at 457 mm, inside the upper band.
Cut-Length Tolerance on Seamless WNR 2.4856 Pipe
A cut length of seamless WNR 2.4856 pipe is never delivered short: the whole allowance sits on the plus side and is keyed to outside diameter.
| Outside Diameter | Cut-Length Tolerance, in. (mm) |
|---|---|
| Under 2 in. (50.8 mm) | +1/8 (3.2) / 0 |
| 2 in. (50.8 mm) and over | +3/16 (4.8) / 0 |
These figures hold for cut lengths up to 7.3 m (24 ft). Past 7.3 m, each further 3 m (10 ft) or part of it adds 3.2 mm (1/8 in.) to the plus allowance, with no more than 12.7 mm (1/2 in.) added in total. Random lengths are agreed with you when the order is placed.
Fabrication Notes for Seamless Inconel 625 Pipe
Seamless Inconel 625 pipe leaves the mill in the heat-treated condition of the grade ordered, and the certificate values describe it in that state. ASTM B444 cautions that hot working or reannealing may change properties significantly, depending on working history and temperatures, so properties after hot bending or a further anneal in the fabrication shop are no longer represented by the original certificate values.
Two order options matter at this stage. Grade 2 can be specified with or without the stabilization anneal, which the standard gives as a step to increase resistance to sensitization, so say on the order whether you want it. Where your shop will hot form the pipe, hot forming quality is furnished to chemical requirements and surface inspection only, with no tensile properties required. Ends arrive plain cut and deburred, leaving weld preparation to your own procedure.
Seamless Nickel Alloy 625 Pipe Against 718 and C276
Inconel 718 seamless pipes come in one condition only, solution annealed plus precipitation hardened, with minimums of 1034 MPa (150 ksi) tensile strength, 862 MPa (125 ksi) yield strength and 20% elongation. Seamless nickel alloy 625 pipe stays annealed: Grade 1 is held to 827 MPa tensile and 414 MPa yield, Grade 2 to 690 MPa and 276 MPa, and both to 30% elongation. The choice is between the higher age-hardened minimums of 718 and the two annealed grades of 625.
Alloy C276 seamless pipes are made to a different product standard under a different UNS number, so moving a line from one alloy to the other changes the specification and the designation on the certificate, not only the alloy name. Send the process media, concentration and chloride level with the line class, and we quote each alloy against its own standard.
Industrial Applications of Seamless 625 Pipe
Process, offshore, marine, power, aerospace and furnace piping account for the bulk of the duties this pipe is ordered for.
Subsea and Downhole Oil and Gas
Downhole tubulars, control lines, subsea wellhead piping and riser tubing are typical oil and gas uses, along with the inner liners of flexible pipe, all cut from seamless lengths.
Seawater and Desalination Systems
Seawater piping in marine and offshore service, and the heat exchanger lines of desalination plants, take UNS N06625 seamless pipe where seawater runs through the line for the whole of its service life.
Flue Gas Desulfurization in Power Plants
Power stations route acid condensate through flue gas desulfurization systems, and the piping in those circuits, together with boiler tubing, is a regular power generation order for this grade.
Aerospace Ducting and Fluid Lines
Engine ducting and exhaust sections are built from the alloy, while the smaller seamless sizes serve hydraulic and fuel lines, each length hydrostatically or electrically tested before it is released.
Furnace Retorts and Muffles
Heat-treatment furnaces use retort tubes and muffles made from the larger seamless sizes, where the pipe forms the chamber that holds the furnace load.
Export Packing for Seamless 2.4856 Pipe
Packing
Bundles or wooden cases sized to the OD, with plastic caps on both ends of every seamless 2.4856 pipe.
Piece marking
Lengths of 19.0 mm OD and over that are longer than 914 mm carry the manufacturer's name, UNS N06625, the letters ASTM with the specification number, the heat number and the nominal size; smaller or shorter pieces are marked one by one or on a tag fixed to the bundle.
Package marking
The bundle or case label also states the condition, so Grade 1 and Grade 2 are told apart before unpacking.
Freight terms
CIF, FOB or CFR, set for each shipment when we quote the Grade 1 or Grade 2 lines.
Paperwork
EN 10204 3.1 (3.2 on request) material test certificate, raw material certificate and heat treatment charts.
Dispatch
From stock or to a mill production slot, with the date confirmed in the quotation.
Alloy 625 Seamless Pipe Price per kg
Alloy 625 seamless pipe to ASTM B444 carries an indicative price of USD 24 to 55 per kg. Where a given order lands in that band follows the nickel, molybdenum and niobium markets, the grade written on the order, the OD, wall and cut length, the lot size, and any testing added beyond the standard. Send your size list with the grade for a firm quotation.
Indicative price, Inconel 625 Seamless Pipes
USD 24 to 55 per kg
Indicative only. Send your sizes and specification to Thaida for a firm quotation.
- Outside diameter
- Wall thickness
- Length
- Quantity
- Testing and certification
- Nickel price
- Molybdenum price
From Our Chonburi Mill to Your Project
We cold work and heat treat this pipe at our factory, 154 Moo.1 Map Phai, Ban Bueng, Chonburi 20170, Thailand. Enquiries, line-class checks and export papers are handled at our office, 89/18 Moo.15 Enterprize Park, Bangna-Trad Road, Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand. Projects inside Thailand are supplied direct, and export orders ship to Singapore, Malaysia, Vietnam, Indonesia, the Philippines and India.
Factory154 Moo.1 Map Phai, Ban Bueng,
Chonburi 20170, Thailand
Chonburi 20170, Thailand
Office89/18 Moo.15 Enterprize Park, Bangna-Trad Road,
Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand
Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand
Exporting to
- Singapore
- Malaysia
- Vietnam
- Indonesia
- Philippines
- India
Seamless N06625 Pipe FAQ
Should I order Grade 1 or Grade 2 Inconel 625 seamless pipe?
Order Grade 1 when the design leans on room-temperature strength: its 414 MPa yield minimum is well above the 276 MPa of Grade 2. Order Grade 2 when the line calls for creep and rupture resistance. Write the grade on every line item, because both grades carry one UNS number under one standard.
Which grade is supplied when the order does not name one?
Grade 1, the annealed condition. ASTM B444 makes it the default, so an order that is silent on grade is filled and reported as Grade 1. If your piping specification calls for Grade 2, add it to the purchase order before release, since changing grade afterwards means a different heat treatment.
What do the ASTM B444 anneal temperatures mean for each grade?
They are minimum mill heat-treatment temperatures, not service ratings. Grade 1 is annealed at 871 °C (1600 °F) or above. Grade 2 is solution annealed at 1093 °C (2000 °F) or above, with or without a further stabilization anneal at 982 °C (1800 °F) minimum, which your order should state.
How close to the ordered cut length will the pipe be?
Never under it. Up to 7.3 m, pipe below 50.8 mm OD may run up to 3.2 mm long and larger pipe up to 4.8 mm long. Longer cuts gain 3.2 mm of allowance per extra 3 m, with the added allowance capped at 12.7 mm, so plan trim on spools that need an exact fit-up length.
Should I choose Alloy 625 or Alloy 718 for a high-strength line?
Choose 718 when strength governs: its 862 MPa yield minimum in the precipitation-hardened condition is far above the 414 MPa of Grade 1 625. Choose 625 when you want an annealed pipe with 30% elongation for bending and forming, or a Grade 2 option for creep and rupture duty.
What OD tolerance applies to seamless 625 pipe above 219 mm?
Up to 356 mm, the OD may run 1.57 mm over or 0.79 mm under nominal; from 356 mm to our 457 mm limit, 3.18 mm over and the same 0.79 mm under. Because the larger share of the allowance is on the plus side, check flange bores and fit-up clearances against the upper figure.
What size range of UNS N06625 seamless pipe can you produce?
The smallest pipe we draw is 6 mm OD and the largest 457 mm, with wall thickness between 1 mm and 35 mm and lengths to 18 m. Give each item as a nominal pipe size and schedule; where a schedule would put the wall above 35 mm, we propose the nearest size we can make at quotation.
Which documents come with an Alloy 625 seamless pipe shipment?
An EN 10204 3.1 (3.2 on request) material test certificate with the heat analysis, tension results, the grade and condition supplied and the hydrostatic or electric test record, plus raw material certificates and heat treatment charts. Grain size or corrosion test reports are added when your order requests those supplementary tests.
Request a Quote for Inconel 625 Seamless Pipes
or email sales@thaida.co.th