ASTM A420/A420M-00
Piping Fittings of Wrought Carbon Steel and Alloy Steel for
Low Temperature Service
Grade	Composition, %
	C	Mn	P	S	Si	Ni	Cu	Cr	Mo	V	Nb
WPL6(1)(2)	0.30	0.60-1.35	0.035	0.040	0.15-0.30	0.40	0.40	0.30	0.12	0.08	0.02
WPL9	0.20	0.40-1.06	0.030	0.030	-	1.60-2.24	0.75-1.25	-	-	-	-
GENERAL NOTE:
All values are maximum unless otherwise indicated.
NOTES:
(1) For each reduction of 0.01% C below 0.30%, an increase of 0.05%
Mn above 1.06% will be permitted, up to a maximum of 1.35%.
(2) Fittings made from forgings may have 1.35% max Mn.
Tensile Requirements					WPL6			WPL9
Tensile Strength, min, ksi [MPa]					60-85[415-585]			63-88[435-610]
Yield Strength, min, ksi [MPa]					35[240]			46[315]
					Wall thickness			Elongation Requirements
					in	mm		Longitudinal		Transverse
								WPL6	WPL9	WPL6	WPL9
Standard round specimen, or small								22	20	12	-
proportional specimen, min % in 4D
Rectangular Specimen for wall thickness					³0.312	³7.94		30	28	16.5	18
0.312in [7.94mm] and over, and for all small
sizes tested in full section; min % in 2in[50mm]
Rectangular Specimen for wall thickness					0.281	7.14		28.5	26.5	15.5	17.0
less than 0.312in [7.94mm]; min % in					0.250	6.35		27.0	25.0	14.5	16.0
2 in[50mm] (0.5in [12.7mm] wide specimen)					0.219	5.56		25.5	23.5	-	-
					0.188	4.76		24.0	22.0	-	-
					0.156	3.97		22.5	20.5	-	-
					0.125	3.17		21.0	19.0	-	-
					0.094	2.38		19.5	17.5	-	-
					0.062	1.59		18.0	16.0	-	-
Where the wall thickness lies between two values above, the min elongation value is determined
by the following equations:
		WPL6			WPL9
Longitudinal		E=48t+15.00			E=48t+13.00
Transverse		E=32t+6.50			E=32t+8.00
E = elongation in 2in[50mm], %
t = actual thickness of specimen, in[mm]