ASTM A420

ASTM A420: American Society for Testing and Materials
Piping Fittings of Wrought Carbon Steel and Alloy Steel for Low-Temperature Service

ASTM A420: American Society for Testing and Materials
Piping Fittings of Wrought Carbon Steel and Alloy Steel for Low-Temperature Service

Tensile Requirements
Requirement	Grade
	WPL6		WPL9		WPL3		WPL8
Tensile strength, min ksi [MPa]	60 [415] ? 85 [585]		63 [435] ? 88 [610]		65 [450] ? 90 [620]		100 [690] ? 125 [865]
Yield strength, min ksi [MPa]	35 [240]		46 [315]		35 [240]		75 [515]
Elongation Requirements	Grade
	WPL6		WPL9		WPL3		WPL8
	Longitudinal	Transverse	Longitudinal	Transverse	Longitudinal	Transverse	Longitudinal	Transverse
Standard round specimen, or small proportional specimen,min % in 4 D	22	12	20	...	22	14	16	...
Rectangular specimen for wall thickness 5?16 in. [7.94 mm] and over, and for all small sizes tested in full section; min % in 2 in. or 50 mm	30	16.5	28	18	30	20	22	...

Rectangular specimen for wall thickness less than 5?16 in [7.94 mm]; min % in 2 in. or 50 mm (1?2-in. [12.7- mm] wide specimen)	A	A	A	A	A	A	A	...
A For each 1?32 in. [0.79 mm] decrease in wall thickness below 5?16 in. [7.94 mm], a deduction of 1.5 %(grades WPL6, WPL9, and WPL3) or 1.25 % (WPL8) for longitudinal and 1.0 % (grades WPL6, WPL9 and WPL3) for transverse from the values shown above is permitted. The following table gives the minimum value for various wall thicknesses:

Chemical Requirements
Grade A	Composition %
Grade A	C	Mn	P	S	Si	Ni	Cr	Mo	Cu	Cb	V
WPL6	0.30	1.50-1.35	0.035	0.04	0.15-0.40	0.40	0.3	0.12	0.40	0.02^B	0.08
WPL9	0.20	0.40-1.06	0.030	0.03	...	1.60-2.24			0.75-1.25
WPL3 C	0.20	0.31-0.64	0.05	0.05	0.13-0.37	3.2-3.8			...
WPL8 D	0.13	0.90	0.30	0.03	0.13-0.37	8.4-9.6			...
A When fittings are of welded construction, the symbols above shall be supplemented by the letter"W".
B By agreement,the limit for Columbium may be increased up to 0.05% on heat analysis and 0.06% on product analysis.
C Fittings made from plate or forgings may have 0.90% max manganese.
D Fittings made from plate may have 0.98% maxmanganese.