Aluminium and aluminium alloys · Сплав AL4 - 3.1325

AL4 (3.1325) Aluminum Alloy: An Expert Review of Characteristics

Technical parameters and specifications of AL4 (3.1325) alloy

Regulatory Standard	Parameter	Value
Target	Parameter	EN
purpose		28839
		–
		Technical
		conditions
		and
		mechanical
		properties
		of fasteners
		made of
		non-ferrous
		metals
		(bolts
Target purpose	Parameter	screws
Target purpose	Parameter	studs
Target	Parameter	nuts
purpose		with
		metric
		thread)
Target	Value	Production
purpose		of high-strength
		fastening
		elements
Target	Parameter	EN
purpose		28839
		–
		Technical
		conditions
		and
		mechanical
		properties
		of fasteners
		made of
		non-ferrous
		metals
		(bolts
Target purpose	Parameter	screws
Target purpose	Parameter	studs
Target	Parameter	nuts
purpose		with
		metric
		thread)
Target	Value	Production
purpose		of high-strength
		fastening
		elements
Alternative	Parameter	EN
identifiers		28839
		–
		Technical
		conditions
		and
		mechanical
		properties
		of fasteners
		made of
		non-ferrous
		metals
		(bolts
Alternative identifiers	Parameter	screws
Alternative identifiers	Parameter	studs
Alternative	Parameter	nuts
identifiers		with
		metric
		thread)
Alternative identifiers	Value	W-Nr / DIN
Alternative	Parameter	EN
identifiers		28839
		–
		Technical
		conditions
		and
		mechanical
		properties
		of fasteners
		made of
		non-ferrous
		metals
		(bolts
Alternative identifiers	Parameter	screws
Alternative identifiers	Parameter	studs
Alternative	Parameter	nuts
identifiers		with
		metric
		thread)
Alternative identifiers	Value	3.1325

AL4 alloy is a structural aluminum material specially designed for the manufacture of metric fasteners in the nominal diameter range from M1.6 to M39. EV Group China experts emphasize that copper is the key alloying component in this alloy. It is copper that provides the optimal balance between maintaining the ductility of the aluminum base and achieving high indicators of hardness, creep resistance, and fatigue strength, especially at elevated operating temperatures. This characteristic makes AL4 alloy indispensable in critical assemblies where reliability and durability are required.

Chemical composition of AL4 alloy (in % ratio)

Si	Parameter	Value
0.2-0.8	Mn	0.4-1
0.2-0.8	Cr	<0.1
0.2-0.8	Cu	3.5-4.5
0.2-0.8	Mg	0.4-1
0.2-0.8	Zn	<0.25
0.2-0.8	Fe	<0.7
0.2-0.8	Zr + Ti	<0.25
0.2-0.8	Impurities	0.15 max
0.2-0.8	Al	remainder

Mechanical properties of AL4 (3.1325) material

Nominal thread diameter (d)	Parameter	Value
d	Tensile	420
≤	strength
M10	(Rm),
	MPa


d	Yield	290
≤	strength
M10	(Rp0.2),
	MPa


d	Elongation	6
≤	(A),
M10	%

M10	Tensile	380
<	strength
d	(Rm),
≤	MPa
M39

M10	Yield	260
<	strength
d	(Rp0.2),
≤	MPa
M39
M10	Elongation	10
<	(A),
d	%
≤
M39

International analogues and compliance of grade 3.1325

Germany (DIN)	Parameter	Value
European Union (EN)	Parameter	3.1325
European Union (EN)	Parameter	AlCuMg1
European Union (EN)	Value	EN AW-AlCu4MgSi (AW-2017)
USA (ASTM/UNS)	Parameter	3.1325
USA (ASTM/UNS)	Parameter	AlCuMg1
USA (ASTM/UNS)	Value	A92017
Russia (GOST)	Parameter	3.1325
Russia (GOST)	Parameter	AlCuMg1
Russia (GOST)	Value	D1 (Duralumin)