norme ASTM

Gli standard ASTM vengono utilizzati per definire il processo di produzione e la composizione chimica di materiali come i tubi, raccordi, e flange. Questi standard assegnano “Gradi” per indicare proprietà chimiche specifiche, come le percentuali di carbonio, magnesio,

Ex

Carbon steel pipes: Grade A or
Stainless steel pipes: Grade TP304 or
Carbon steel fittings: Grade WPB

Ch

Below are examples of ASTM grades and their chemical requirements:

Flanges: ASTM A182 (Grades F304, F304L, F316L)
Pipes: ASTM A312 (Grades TP304, TP304L, TP316L)
Fittings: ASTM A403 (Grades WP304, WP304L, WP316L)

Inoltre, you will find a table summarizing commonly used ASTM grades for pipes, raccordi, flange, valves, bolts, and nuts grouped by their applications.

Special Note on ASTM A105

ASTM A105 does not include a grade designation. Sometimes, the term A105N is used. IL “N” does not signify a grade but refers to normalizing, a heat treatment process for ferrous metals. Normalizing helps relieve internal stresses caused by heat treatment, casting, or forming.

CHEMICAL REQUIREMENTS COMPOSITION, %

Flanges ASTM A182
Grado	C	Mn	P	S	E	In	Cr	Mo
F304	0.08	2	0.045	0.03	1	8 – 11	18 – 20
F304L	0.03	2	0.045	0.03	1	8 – 13	18 – 20
F316L	0.03	2	0.045	0.03	1	10 – 15	16 – 18	2 – 3
Nota: Grades F304, F304L, and F316L shall have a maximum Nitrogen content of 0.10%.
Pipes ASTM A312
Grado	C	Mn	P	S	E	Cr	In	Mo
TP 304	0.08	2	0.045	0.03	1	18 – 20	8 – 11
TP 304L	0.035	2	0.045	0.03	1	18 – 20	8 – 13
TP 316L	0.035	2	0.045	0.03	1	16 – 18	10 – 14	2 – 3
Nota: For small diameter or thin walls or both, where many drawing passes are required, a Carbon maximum of 0.040% is necessary in grades TP304L and TP316L. Small outside diameter tubes are defined as those less than 0.50 In. [12.7 mm] in outside diameter and light wall tubes as those less than 0.049 In. [1.20 mm] in average wall thickness (0.044 In. [1.10 mm] in minimum wall thickness).
Fittings ASTM A403
Grado	C (1)	Mn (1)	P (1)	S (1)	E (1)	In	Cr	Mo
WP 304	0.08	2	0.045	0.03	1	8 – 11	18 – 20
WP 304L	0.03 (2)	2	0.045	0.03	1	8 – 12	18 – 20
WP 316L	0.03 (2)	2	0.045	0.03	1	10 – 14 (3)	16 – 18	2 – 3
Note: (1) Massimo, unless otherwise indicated. (2) For small diameter or thin walls or both, where many drawing passes are required, a Carbon maximum of 0.040% is necessary in grades TP304L and TP316L. Small outside diameter tubes are defined as those less than 0.50 In. [12.7 mm] in outside diameter and light wall tubes as those less than 0.049 In. [1.20 mm] in average wall thickness (0.044 In. [1.10 mm] in minimum wall thickness). (3) On pierced tubing, the Nickel may be 11.0-16.0%.

FREQUENTLY USED ASTM GRADES

Materiale	Pipes	Fttg	Flg	Valves	Bolts E Nuts
Acciaio al carbonio	A106 Gr A	A234 Gr WPA	A105	A216 Gr WCB	A193 Gr B7 A194 Gr 2H
	A106 Gr B	A234 Gr WPB	A105	A216 Gr WCB
	A106 Gr C	A234 Gr WPC	A105	A216 Gr WCB

Acciaio al carbonio Alloy High-Temp	A335 Gr P1	A234 Gr WP1	A182 Gr F1	A217 Gr WC1	A193 Gr B7 A194 Gr 2H
	A335 Gr P11	A234 Gr WP11	A182 Gr F11	A217 Gr WC6
	A335 Gr P12	A234 Gr WP12	A182 Gr F12	A217 Gr WC6
	A335 Gr P22	A234 Gr WP22	A182 Gr F22	A217 Gr WC9
	A335 Gr P5	A234 Gr WP5	A182 Gr F5	A217 Gr C5
	A335 Gr P9	A234 Gr WP9	A182 Gr F9	A217 Gr C12

Acciaio al carbonio Alloy Low-Temp	A333 Gr 6	A420 Gr WPL6	A350 Gr LF2	A352 Gr LCB	A320 Gr L7 A194 Gr 7
Acciaio al carbonio Alloy Low-Temp	A333 Gr 3	A420 Gr WPL3	A350 Gr LF3	A352 Gr LC3	A320 Gr L7 A194 Gr 7

Austenitico Stainless Acciaio	A312 Gr TP304	A403 Gr WP304	A182 Gr F304	A182 Gr F304	A193 Gr B8 A194 Gr 8
	A312 Gr TP316	A403 Gr WP316	A182 Gr F316	A182 Gr F316
	A312 Gr TP321	A403 Gr WP321	A182 Gr F321	A182 Gr F321
	A312 Gr TP347	A403 Gr WP347	A182 Gr F347	A182 Gr F347
Materiale	Pipes	Fttg	Flg	Valves	Bolts E Nuts