This specification covers forged low alloy and stainless steel piping components for use in pressure systems. Included are flanges, fittings, valves, and similar parts to specified dimensions or to dimensional standards.

TABLE 1 Heat Treating Requirements
Grade	Heat Treat Type	Austenitizing/Solutioning		Cooling	Quenching Cool	Tempering Temperature,
		Temperature, Minimum		Media		Minimum or
			or Range, °F [°C]A		Below °F [°C]	Range, °F [°C]
			Ferritic-Austenitic Stainless Steels
F 50	solution treat and quench	1925	[1050]	liquid	500	[260]	B
F 51	solution treat and quench	1870	[1020]	liquid	500	[260]	B
F 52 C				liquid	500	[260]	B
F 53	solution treat and quench	1880	[1025]	liquid	500	[260]	B
F 54	solution treat and quench	1920-2060 [1050-1125]		liquid	500	[260]	B
F 55	solution treat and quench	2010-2085 [1100-1140]		liquid	500	[260]	B
F 57	solution treat and quench	1940	[1060]	liquid	175	[80]	B
F 59	solution treat and quench	1975-2050 [1080-1120]		liquid	500	[260]	B
F 60	solution treat and quench	1870	[1020]	liquid	500	[260]	B

A Minimum unless temperature range is listed.
B Not applicable.
C Grade F 52 shall be solution treated at 1825 to 1875 °F [995 to 1025 °C] 30 min/in. of thickness and water quenched.

DThe cooling media for Grade F 65 shall be quenching in water or rapidly cooling by other means.

TABLE 2 Chemical Requirements A

Identifi-

UNS

Grade

Composition, %

cation

Desig-

Carbon

Manga-

Phos-

Sulfur

Silicon

Nickel

Chromium

Molybde-

Colum-

Titan-

Other

Symbol

nation

nese

phorus

num

bium

ium

Elements

Ferritic-Austenitic Stainless Steels

F 50

S31200

25 chromium, 6 nickel,

0.03

2

0.045

0.03

1

5.5–6.5

24.0–26.0

1.20–2.00

...

...

N 0.14–0.20

modified with nitrogen

S31803

22 chromium, 5.5

0.03

2

0.03

0.02

1

4.5–6.5

21.0–23.0

2.5–3.5

...

...

N 0.08–0.20

F 51

nickel, modified with

nitrogen

S32950

26 chromium, 3.5

0.03

2

0.035

0.01

0.6

3.5–5.2

26.0–29.0

1.00–2.50

...

...

N 0.15–0.35

F 52

nickel, 1.0 molybdenum

S32750

25 chromium, 7 nickel,

0.03

1.2

0.035

0.02

0.8

6.0–8.0

24.0–26.0

3.0–5.0

...

...

N 0.24–0.32

F 53

4 molybdenum,

Cu 0.50

modified with nitrogen

2507G

S39274

25 chromium, 7 nickel,

0.03

1

0.03

0.02

0.8

6.0–8.0

24.0–26.0

2.5–3.5

...

...

N 0.24–0.32

F 54

modified with nitrogen

Cu 0.20–0.80

and tungsten

W 1.50–2.50

S32760

25 chromium, 7 nickel,

0.03

1

0.03

0.01

1

6.0–8.0

24.0–26.0

3.0–4.0

...

...

N 0.20–0.30

F 55

3.5 molybdenum,

Cu 0.50–1.00

modified with nitrogen

W 0.50–1.00O

and tungsten

S39277

26 chromium, 7 nickel,

0.025

0.8

0.025

0.002

0.8

6.5–8.0

24.0–26.0

3.0–4.0

...

...

Cu 1.20–2.00

F 57

3.7 molybdenum

W 0.80–1.20

N 0.23–0.33

S32520

25 chromium, 6.5

0.03

1.5

0.035

0.02

0.8

5.5–8.0

24.0–26.0

3.0–5.0

...

...

N 0.20–0.35

F 59

nickel, 4 molybdenum

Cu 0.50–3.00

with nitrogen

S32205

22 chromium, 5.5

0.03

2

0.03

0.02

1

4.5–6.5

22.0–23.0

3.0–3.5

...

...

N 0.14–0.20

F 60

nickel, 3 molybdenum,

modified with nitrogen

2205G

S32550

26 chromium, 6 nickel,

0.04

1.5

0.04

0.03

1

4.5–6.5

24.0–27.0

2.9–3.9

...

...

Cu 1.50–2.50

F 61

3.5 molybdenum with

N 0.10–0.25

nitrogen and copper

255G

S32906

29 chromium, 6.5

0.03

0.80–1.50 0.030

0.03

0.8

5.8–7.5

28.0–30.0

1.5–2.6

...

...

Cu 0.80

F 65

nickel, 2 molybdenum

N 0.30–0.40

with nitrogen

S32202

22 chromium, 2.0

0.03

2

0.04

0.01

1

1.00–2.80

21.5–24.0

0.45

...

...

N 0.18–0.26

F 66

nickel, 0.25

molybdenum with

nitrogen

S32506

25 chromium, 6 nickel,

0.03

1

0.04

0.015

0.9

5.5–7.2

24.0–26.0

3.0–3.5

...

...

N 0.08–0.20

F 67

3 molybdenum, with

W 0.05–0.30

nitrogen

and tungsten

A All values are maximum unless otherwise stated. Where ellipses (...) appear in this table, there is no requirement and analysis for the element need not be determined or reported.
B Grade F 2 was formerly assigned to the 1 % chromium, 0.5 % molybdenum grade which is now Grade F 12.
C The present grade F 5a (0.25 max carbon) previous to 1955 was assigned the identification symbol F 5. Identification symbol F 5 in 1955 was assigned to the 0.15 max carbon grade to be consistent with ASTM specifications for other products such as pipe, tubing, bolting, welding fittings, and the like.
D Applies to both heat and product analyses.
E For Grade F22V, rare earth metals (REM) may be added in place of calcium, subject to agreement between the producer and the purchaser. In that case the total amount of REM shall be determined and reported.

TABLE 3 Tensile and Hardness RequirementsA
Grade Symbol	Tensile Strength, min, ksi [MPa]		Yield Strength, min, ksi [MPa]B	Elongation in 2 in. [50 mm] or 4D, min, %	Reduction of Area, min, %	Brinell Hardness Number, HBW
Ferritic-Austenitic Stainless Steels
F 50	100–130	65 [450]	25	50	. . .
	[690–900]
F 51	90 [620]	65 [450]	25	45	. . .
F 52	100 [690]	70 [485]	15	. . .	. . .
F 53	116 [800]G	80 [550]G	15	. . .	310 max
F 54	116 [800]	80 [550]	15	30	310 max
F 55	109–130	80 [550]	25	45	. . .
	[750–895]
F 57	118 [820]	85 [585]	25	50	. . .
F 59	112 [770]	80 [550]	25	40	. . .
F 60	95 [655]	65 [450]	25	45	. . .
F 61	109 [750]	80 [550]	25	50	. . .
F 65	109 [750]	80 [550]	25	. . .	. . .
F 66	94 [650]	65 [450]	30	. . .	290 max
F 67	90 [620]	65 [450]	18	. . .	302

A Where ellipses appear in this table, there is no requirement and the test for the value need neither be performed nor a value reported.
B Determined by the 0.2 % offset method. For ferritic steels only, the 0.5 % extension-under-load method may also be used.
C For sections over 5 in. [130 mm] in thickness, the minimum tensile strength shall be 70 ksi [485 MPa].
D For sections over 5 in. [130 mm] in thickness, the minimum tensile strength shall be 65 ksi [450 MPa].
E Longitudinal. The transverse elongation shall be 25 % in 2 in. or 50 mm, min.
F Longitudinal. The transverse reduction of area shall be 45 % min.
G For sections over 2 in. [50 mm] in thickness, the minimum tensile strength shall be 106 ksi [730 MPa]; the minimum yield strength shall be 75 ksi [515 MPa]