Scope: This specification covers two general classes, WP and CR, of wrought ferritic, ferritic/austenitic, and martensitic stainless steel fittings of seamless and welded construction covered by the latest revision of Specification A960/A960M.
NOTE 1—Where an ellipsis (. . .) appears in this table, there is no requirement.
TABLE 1 Chemical Requirements.

TABLE 1 Chemical Requirements
Composition, %
GradeA
Grade	Grade	UNS	C,	MnB	P,	S,	Si,	NiB	Cr	Mo	CuB	NB	Ti	Other
WP	CR		max		max	max	max
						Ferritic Steels
WP27	CR27	S44627	0.01	0.75	0.02	0.02	0.4	0.5	25.0–	0.75–	0.2	0.015	. . .	Cb
									27.5	1.5				0.05–0.20
WP33	CR33	S44626	0.06	0.75	0.04	0.02	0.75	0.5	25.0–	0.75–	0.2	0.04	0.20–1.00	. . .
									27	1.5			(7×(C+N)) min
WP429	CR429	S42900	0.12	1	0.04	0.03	0.75	0.5	14.0–	. . .	. . .	. . .	. . .	. . .
									16
WP430	CR430	S43000	0.12	1	0.04	0.03	1	0.5	16.0–	. . .	. . .	. . .	. . .	. . .
									18
WP430TI	CR430Ti	S43036	0.1	1	0.04	0.03	1	0.75	16.0–	. . .	. . .	. . .	(5×C) min 0.75	. . .
									19.5				max
WP446	CR446	S44600	0.2	1.5	0.04	0.03	0.75	0.5	23.0–	. . .	. . .	0.25	. . .	. . .
									27

Martensitic Steels
WPS31803	CRS31803	S31803	0.03	2	0.03	0.02	1	4.5–	21.0–	2.5–	. . .	0.08–	. . .	. . .
								6.5	23	3.5		0.2
WPS32101	CRS32101	S32101	0.04	4.0–	0.04	0.03	1	1.35–	21.0–	0.10–	0.10–	0.20–	. . .	. . .
				6				1.7	22	0.8	0.8	0.25
WPS32202	CRS32202	S32202	0.03	2	0.04	0.01	1	1.00–	21.5–	0.45	. . .	0.18–	. . .	. . .
								2.8	24			0.26
WPS32750	CRS32750	S32750	0.03	1.2	0.035	0.02	0.8	6.0–	24.0–	3.0–	0.5	0.24–	. . .	. . .
								8	26	5		0.32
WPS32950	CRS32950	S32950	0.03	2	0.035	0.01	0.6	3.5–	26.0–	1.00–    . . .		0.15–	. . .	. . .
								5.2	29	2.5		0.35
WPS32760	CRS32760	S32760	0.03	1	0.03	0.01	1	6.0–	24.0–	3.0–	0.50–	0.20–	. . .	W
								8	26.0C	4.0C	1	0.30C		0.50–1.00
WPS39274	CRS39724	S32974	0.03	1	0.03	0.02	0.8	6.0–	24.0–	2.50–	0.20–	0.24–	. . .	W
								8	26	3.50C	0.8	0.32		1.50–2.50
WPS32550	CRS32550	S32550	0.04	1.5	0.04	0.03	1	4.5–	24.0–	2.9–	1.50–	0.10–	. . .	. . .
								6.5	27	3.9	2.5	0.25
WPS32205	CRS32205	S32205	0.03	2	0.03	0.02	1	4.5–	22.0–	3.0–	. . .	0.14–	. . .	. . .
								6.5	23	3.5		0.2

Martensitic Steels
WP410	CR410	S41000	0.15	1	0.04	0.03	1	0.5	11.5–	. . .	. . .	. . .	. . .	. . .
								max	13.5
WPS41008	CRS41008	S41008	0.08	1	0.04	0.03	1	0.6	11.5–	. . .	. . .	. . .	. . .	. . .
									13.5
WPS41500	CRS41500	S41500	0.05	0.50–	0.03	0.03	0.6	3.5–	11.5–	0.50–    . . .		. . .	. . .	W
				1				5.5	14	1				0.50–1.00

A Naming system developed and applied by ASTM International.
B Maximum unless otherwise indicated.
C % Cr + 3.3 × % Mo + 16 × % N = 40 min.

TABLE 2 Heat Treatment
Stainless Steel	All WP and CR Grades	Temperature	Cooling	Tempering
				Temperature
Ferritic	All	$ 1200 °F [650 °C]	As appropriate for grade	Not specified
Ferritic/Austenitic	S31803	1870–2010 °F	Water quench or	Not required
		[1020–1100 °C]	rapidly cooled by
			other means
	S32101	1870 °F [1020 °C] min	Water quench or	Not required
			rapidly cooled by
			other means
	S32202	1870–1975 °F	Water quench or	Not required
		[1020–1080 °C]	rapidly cooled by
			other means
	S32205	1870–2010 °F	Water quench	Not required
		[1020–1100 °C]
	S32750	1920–2060 °F	Water quench or	Not required
		[1025–1125 °C]	rapidly cooled by
			other means
	S32760	2010–2085 °F	Water quench or	Not required
		[1100–1140 °C]	rapidly cooled by
			other means
	S39274	1920–2060 °F	Water quench or	Not required
		[1025–1125 °C]	rapidly cooled by
			other means
	S32550	1950–2060 °FA	Water quench	Not required
		[1065–1125 °C]A
	S32950	Not specified	Not specified	Not required
Martensitic	S41000	$ 1200°F [650°C]	Not specified	Not specified
	S41008	>1200°F [650°C]	In still air	Not specified
			as appropriate
			for grade
	S41500	$ 1750 °F [955 °C]	Air cool to # 200 °F	1050–1150 °F
			[95 °C] prior to any	[565–620 °C]
			optional intermediate
			temper and prior to
			final temper.
			other means
	S32101	1870 °F [1020 °C] min	Water quench or	Not required
			rapidly cooled by
			other means
	S32202	1870–1975 °F	Water quench or	Not required
		[1020–1080 °C]	rapidly cooled by
			other means
	S32205	1870–2010 °F	Water quench	Not required
		[1020–1100 °C]
	S32750	1920–2060 °F	Water quench or	Not required
		[1025–1125 °C]	rapidly cooled by
			other means
	S32760	2010–2085 °F	Water quench or	Not required
		[1100–1140 °C]	rapidly cooled by
			other means
	S39274	1920–2060 °F	Water quench or	Not required
		[1025–1125 °C]	rapidly cooled by
			other means
	S32550	1950–2060 °FA	Water quench	Not required
		[1065–1125 °C]A
	S32950	Not specified	Not specified	Not required

A The higher temperature (2000 to 2060 °F [1095 to 1125 °C]) PWHT is best used on welded product—the lower temperature PWHT
(1950 to 2010 °F [1065 to 1100 °C]) is best used on wrought or seamless products only.

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
F 49	115 [795]	60 [415]	35	40	. . .
F 56	73 [500]	27 [185]	30	35	. . .
F 58	109 [750]	61 [420]	35	50	. . .
F 62	95 [655]	45 [310]	30	50	. . .
F 63	80 [550]	32 [220]	25	. . .	192 max
F 64	90 [620]	40 [275]	35	50	217 max
F 904L	71 [490]	31 [215]	35	. . .	. . .
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.
D. For sections over 5 in. [130 mm] in thickness, the minimum tensile strength shall be 65 ksi [450 MPa].
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]