Chemical Composition

Identification Symbol	Grade	Elements	Composition %
UNS N04400	26 chromium, 6 nickel, 3.5 molybdenum with nitrogen and copper 255	Nickel, minA	63.0
		Copper, max	28.0 min - 34.0 max
		Iron, max	2.5
		Manganese, max	2.0
		Carbon, max	0.3
		Silicon, max	0.5
		Sulfur, max	0.024

Mechanical Properties

Condition and Diameter or Distance Between Parallel Surfaces, in. (mm)	Tensile Strength min, psi (MPa)	Yield Strength (0.2 % offset)A min. psi (MPa)	Elongation in 2 in. or 50 mm (or 4D), min, %	Rockwell Hardness (or equivalent)
Cold-worked (as worked):
Rounds under 1⁄2 (12.7)	110 000 (760)	85 000 (585)	8B	-
Squares, hexagons, and rectangles under 1⁄2 (12.7)	85 000 (585)	55 000 (380)	10B	-
Cold-worked (stress-relieved):
Rounds under 1⁄2 (12.7)	84 000 (580)	50 000 (345)	10B	-
Rounds, 1⁄2 to 31⁄2 (12.7 to 88.9), incl	87 000 (600)	60 000 (415)	20	-
Rounds, over 31⁄2 to 4 (88.9 to 101.6), incl	84 000 (580)	55 000 (380)	20	-
Squares, hexagons and rectangles, 2 (50.8) and under	84 000 (580)	50 000 (345)	20B,C	-
Squares, hexagons and rectangles, over 2 (50.8) to 31⁄8 (79.4), incl	80 000 (552)	50 000 (345)	20	-
Hot-worked (as worked or stress-relieved):
Rounds, squares, and rectangles up to 12 (305), incl, and hexagons 21⁄8 (54) and under	80 000 (552)	40 000 (276)	30D	-
Rounds, squares, and rectangles over 12 (305) to 14 (356), incl	75 000 (517)	40 000 (276)	30	-
Hexagons over 21⁄8 (54) to 4 (102), incl	75 000 (517)	30 000 (207)	25	-
Rings and disks	-	-	-	B 75 to B95
Hot-worked (annealed) or cold-worked (annealed):
Rod and bar, all sizes	70 000 (480)	25 000 (170)	35	-
Rings and disks	-	-	-	B 60 to B75
Forging quality
All sizes	-	-	-	-