Incoloy 825 (Alloy 825) Pipes | ASTM B423 / B705 Supplier

Incoloy 825 (Alloy 825, UNS N08825, 2.4858) Pipe to ASTM B423 and B705

Dinesh Tube India supplies and exports Incoloy 825 pipes from Mumbai for sulphuric acid, phosphoric acid, sour-gas and seawater piping. Incoloy 825, also called Alloy 825 (and often searched as "Inconel 825"), is a nickel-iron-chromium alloy, UNS N08825 (Werkstoff 2.4858), with molybdenum, copper and titanium. We supply seamless pipe to ASTM B423 / ASME SB423 and welded pipe to ASTM B705 / ASME SB705, by NPS and schedule, in the stabilise-annealed condition, with EN 10204 3.1 mill test certificates.

With 38–46% nickel, Alloy 825 is practically immune to chloride stress corrosion cracking. Molybdenum and copper give strong resistance to sulphuric and phosphoric acids, and titanium stabilisation protects against intergranular attack after welding.

Incoloy® is a trademark of the Special Metals group of companies. Dinesh Tube India is an independent supplier; pipes are supplied to UNS N08825 from approved mills, with the producing mill shown on the certificate.

Table of Contents

Which Pipe Specification?
How to Order Incoloy 825 Pipe
Specification & Sizes
Schedule & Weight Table
Heat-Treatment Condition
Chemical Composition
Mechanical Properties
Equivalent Grades
825 vs 316L vs Alloy 20 vs 625
Testing and Inspection
Matching Fittings and Flanges
Where Incoloy 825 Pipe Works Best
FAQs

Incoloy 825 (UNS N08825) seamless and welded pipes to ASTM B423 and B705

Which Incoloy 825 Pipe Specification Do You Need?

Specification	Product	Notes
ASTM B423 / ASME SB423	Seamless pipe and tube	The main seamless specification for N08825
ASTM B705 / ASME SB705	Welded pipe	Larger sizes and thin walls
ASTM B829	General requirements	Tolerances and testing for nickel-alloy seamless pipe and tube
ASTM B163 / B704	Seamless / welded tube	Heat-exchanger and condenser tube, ordered by OD and wall

Note: ASTM A335 covers ferritic alloy-steel pipe (P11, P22, P91) and does not apply to Incoloy 825. Always order 825 pipe to B423 or B705.

How to Order Incoloy 825 Pipe

Specification and grade: for example "ASTM B423 UNS N08825, seamless, annealed" or "ASTM B705 UNS N08825, welded, Class 1".
NPS and schedule: for example 2" Sch 40S; or OD and wall in mm.
Length: random, double random or cut lengths.
Condition: annealed (stabilise annealed) or cold worked.
Ends: plain or bevelled.
Testing and documents: required tests (see below), EN 10204 3.1 or 3.2 certificate, and any third-party inspection.

Incoloy 825 Pipe Schedule and Weight Table

NPS	OD (mm)	Sch 10S Wall (mm)	Sch 10S kg/m	Sch 40S Wall (mm)	Sch 40S kg/m	Sch 80S Wall (mm)	Sch 80S kg/m
1/2"	21.34	2.11	1.04	2.77	1.32	3.73	1.68
3/4"	26.67	2.11	1.33	2.87	1.75	3.91	2.28
1"	33.40	2.77	2.17	3.38	2.59	4.55	3.36
1½"	48.26	2.77	3.22	3.68	4.19	5.08	5.61
2"	60.33	2.77	4.08	3.91	5.64	5.54	7.76
3"	88.90	3.05	6.70	5.49	11.71	7.62	15.84
4"	114.30	3.05	8.68	6.02	16.67	8.56	23.14
6"	168.28	3.40	14.33	7.11	29.30	10.97	44.13
8"	219.08	3.76	20.70	8.18	44.11	12.70	67.02

Weight (kg/m) = (OD − wall) × wall × 0.02557, using density 8.14 g/cm³. Wall thicknesses per ASME B36.19.

Heat-Treatment Condition

Annealed (standard): Alloy 825 pipe is normally supplied stabilise annealed (around 940 °C) and pickled, which gives the best combination of corrosion resistance and ductility.
Cold worked: higher strength, available on request for special duties; check the code allowable stresses before ordering.
After fabrication: hot-formed parts should be re-annealed. Avoid long exposure at 650–760 °C, which can reduce corrosion resistance.

Incoloy 825 Pipe Chemical Composition (UNS N08825, %)

Element	UNS N08825
Nickel (Ni)	38.0–46.0
Chromium (Cr)	19.5–23.5
Molybdenum (Mo)	2.5–3.5
Copper (Cu)	1.5–3.0
Titanium (Ti)	0.6–1.2
Iron (Fe)	22.0 min
Carbon (C), max	0.05
Manganese (Mn), max	1.0
Silicon (Si), max	0.5
Sulphur (S), max	0.03
Aluminium (Al), max	0.2

Incoloy 825 Pipe Mechanical Properties (ASTM B423, Annealed, Minimum)

Tensile Strength	Yield Strength (0.2%)	Elongation	Density
586 MPa (85 ksi)	241 MPa (35 ksi)	30%	8.14 g/cm³

Check the current ASTM B423 / B705 edition and the mill certificate for governing values. ASME pressure-vessel use is normally limited to about 538 °C.

Incoloy 825 Equivalent Grades

Designation	Equivalent
UNS	N08825
Werkstoff Nr.	2.4858
DIN name	NiCr21Mo
JIS	NCF 825
BS	NA 16
AFNOR	NFE30C20DUM
Other names	Alloy 825, Nickel Alloy 825 (sometimes called "Inconel 825")

Note: DIN 1.4558 is Alloy 800 (Incoloy 800), not 825. The correct Werkstoff number for Incoloy 825 is 2.4858.

Incoloy 825 vs 316L vs Alloy 20 vs Inconel 625

Point	316L	Alloy 20	Incoloy 825	Inconel 625
Ni / Cr / Mo (nominal %)	10 / 17 / 2	35 / 20 / 2.5	42 / 21 / 3	61 / 22 / 9
Sulphuric / phosphoric acid	Poor	Very good	Very good	Very good
Chloride stress corrosion cracking	Poor	Very good	Excellent	Excellent
Seawater pitting / crevice	Poor	Fair	Fair	Excellent
Relative cost	Lowest	High	High	Highest

Incoloy 825 is a cost-effective step up from 316L and Alloy 20 where chloride stress corrosion cracking or sour-gas service is a concern. For severe seawater pitting and crevice corrosion, Inconel 625 pipe is the usual next step.

Testing and Inspection

Per ASTM B423 / B705 / B829: hydrostatic or non-destructive electric test on each pipe, tension and flattening (or flare) tests, and dimensional checks.
Welded pipe (B705): Class 1 pipe is radiographed; other classes as ordered.
On request: PMI, intergranular corrosion testing, ultrasonic testing and third-party inspection.

Matching Incoloy 825 Fittings and Flanges

825 Pipe Fittings

Butt-weld elbows, tees, reducers and caps to ASTM B366 WPNICMC (N08825).

825 Flanges

Weld neck, slip-on and blind flanges forged to ASTM B564 N08825.

Other Nickel-Alloy Pipes

Inconel 600, 601, 625, 690 and Incoloy 800 / 800H / 800HT pipe.

Need Incoloy 825 pipe or a price? Send the specification, NPS, schedule, seamless or welded, length and quantity to kamlesh@dineshtube-india.com or call +91 83559 10913. You can also send an enquiry.

Where Incoloy 825 Pipe Works Best

Sulphuric and phosphoric acid: process and transfer lines, pickling plants and fertiliser plants.
Sour oil and gas: production piping, flowlines and clad-pipe liners where H₂S and chlorides are present.
Chloride service: where 316L would suffer chloride stress corrosion cracking.
Limits: only fair resistance to seawater pitting and crevice corrosion; not normally used above about 540 °C, where creep strength and brittle phases govern.

Incoloy 825 Pipe Applications

Sulphuric acid and pickling plants
Phosphoric acid and fertiliser plants
Sour-gas production and process piping
Chemical and petrochemical process lines
Pollution control and flue-gas scrubbers
Nuclear fuel reprocessing and radioactive-waste handling

Acid, sour-gas and chemical process uses of Incoloy 825 pipes

Incoloy 825 Pipes: FAQs

What is Incoloy 825?

Incoloy 825 (Alloy 825, UNS N08825, Werkstoff 2.4858) is a nickel-iron-chromium alloy with about 42% nickel, 21% chromium, 3% molybdenum, 2% copper and titanium. It resists sulphuric and phosphoric acids and chloride stress corrosion cracking.

Is Inconel 825 the same as Incoloy 825?

Yes, the names refer to the same alloy, UNS N08825. Its correct trade name is Incoloy 825; "Inconel" is the name of a different family of higher-nickel alloys such as Inconel 600 and 625.

Which standard covers Incoloy 825 pipe?

Seamless Incoloy 825 pipe is made to ASTM B423 (ASME SB423) and welded pipe to ASTM B705 (ASME SB705), with general requirements in ASTM B829. ASTM A335 does not apply to Incoloy 825.

What is the difference between ASTM B423 and B705?

ASTM B423 covers seamless pipe and tube; ASTM B705 covers welded pipe. Welded pipe is usually lower cost in larger sizes and thin walls; seamless is used for smaller sizes and higher-pressure lines.

What is the DIN or Werkstoff number for Incoloy 825?

The Werkstoff number is 2.4858 (DIN NiCr21Mo). DIN 1.4558 is a different alloy (Alloy 800), so check this when comparing quotes.

How much does Incoloy 825 pipe weigh?

Weight in kg/m = (OD − wall) × wall × 0.02557, with OD and wall in mm. For example, 2" Sch 40S (60.33 × 3.91 mm) weighs about 5.64 kg/m.

What is the price of Incoloy 825 pipe?

The price of Incoloy 825 (Alloy 825) pipe depends on seamless or welded, NPS, schedule, length, quantity, testing and certification, and on nickel prices at the time of order. Send your requirement to kamlesh@dineshtube-india.com or call +91 83559 10913 for a current quote.

Export Destinations for Incoloy 825 Pipes

We supply Incoloy 825 seamless and welded pipes across India to chemical, fertiliser, refinery and oil and gas projects, and export them to Japan, South Korea, Singapore, Malaysia and Indonesia in Asia; the Middle East (UAE, Saudi Arabia, Qatar, Oman, Kuwait); Europe (Spain, Italy and others); and Africa (Egypt, Nigeria, South Africa) on request.

Incoloy 825 (UNS N08825) Seamless & Welded Pipes