INCOLOY® 8252.4858 – UNS N08825 – NiCr21Mo

INCOLOY® alloy 825 (UNS N08825/W.Nr. 2.4858) is a nickel-iron-chromium alloy with additions of molybdenum, copper, and titanium. is designed to provide exceptional resistance to many corrosive environments. The nickel content is sufficient for resistance to chloride-ion stress-corrosion cracking. The nickel, in conjunction with the molybdenum and copper, also gives outstanding resistance to reducing environments such as those containing sulfuric and phosphoric acids. The molybdenum also aids resistance to pitting and crevice corrosion. The alloy’s chromium content confers resistance to a variety of oxidizing substances such as nitric acid, nitrates and oxidizing salt. The titanium addition serves, with an appropriate heat treatment, to stabilize the alloy against sensitization to intergranular corrosion.

ACEQUISA INCOLOY 825 N08825 2.4858


seamless-pipe Seamless Tubes

welded-pipe Welded Tubes  stock
plate Plates  stock
bar Bars  stock
flanges Flanges  stock
accessories Fittings  stock


  • Chemical Processing
  • Pollution-control
  • Oil and gas well piping
  • Nuclear fuel reprocessing
  • Components in Pickling equipment like heating coils, tanks, baskets and chains
  • Acid production

General characteristics

  • Excellent resistance to reducing and oxidizing acids
  • Good resistance to stress-corrosion cracking
  • Satisfactory resistance to localized attack like pitting and crevice corrosion
  • Very resistant to sulfuric and phosphoric acids
  • Good mechanical properties at both room and elevated temperatures up to approximately 1020° F
  • Permission for pressure-vessel use at wall temperatures up to 800°F

Technical information



Alloy 825 – UNS N08825
Products Norm ASTM
Seamless Tubes B-423 B-829
Welded Tubes B-704 B-705 B-751 B-775
Plates B-424
Bars B-425
Flanges B-564
Fittings B-366 B-564

Chemical specifications %


Alloy 825 – UNS N08825
Element Simbol Maximum
Carbon C 0,05
Manganese Mn 1,0
Sulfur S 0,030
Silicon Si 0,50
Nickel Ni 38,0-46,0
Chrome Cr 19,5-23,5
Molybdenum Mo 2,5-3,5
Copper Cu 1,0-3,0
Iron Fe Min. 22,0
Aluminum Al 0,20
Titanium Ti 0,6-1,20

Mechanical Properties

Alloy 825 – UNS N08825
Norm Rm min. Rp 0,2% min. E4d min.% Z min.% T.I.(J) HR B HB
B-423 a 75 (517) 25 (172) 30
b 85 (586) 35 (241) 30
c A Hot-forming quality is furnished to chemical requirements and surface inspection only. No mechanical properties are required
B-424 85 (586) 35 (241) 30 (*)
B-564 85 (586) 35 (241) 30
B-704 85 (586) 35 (241) 30
B-705 85 (586) 35 (241) 30

a = Hot-finished annealed

b = cold-worked annealed

c = hot-forming quality (hot-finished or cold-drawn annealed)

(*) Not applicable to diameters or cross sections under 3⁄32 in. (2.4 mm).