EN 573-3 Grade 3.1355 H18 – High‑Strength Aluminum Alloy for Aerospace Applications

Aluminum DIN 3.1355, known for its use in aircraft industry, is an alloy that offers excellent strength. When in the annealed condition it is readily formed and has good machinability. Though it has a relatively low level of corrosion resistance, it can be machined to a high finish.

Properties

General

Property	Value	Condition	Related Standards
Density	2.77 g/cm³	H18	EN 573-3, EN 1301
	2.78 g/cm³	H18	EN 573-3, EN 1301

Mechanical

Property	Value	Condition	Related Standards	Comment
Elastic modulus	73.0 GPa	H18	EN 573-3, EN 1301
Plane-Strain Fracture Toughnes	22.0 - 35.0 MPa·√m			Typical for Wrought 2000 Series Aluminium
Poisson's ratio	0.33 [-]			Typical for Wrought 2000 Series Aluminium
Shear modulus	27.4 GPa	H18	EN 573-3, EN 1301
Tensile strength	320.0 MPa	H18	EN 573-3, EN 1301

Thermal

Property	Temperature	Value	Condition	Related Standards
Coefficient of thermal expansion	-50 °C	2.11e-05 1/K	H18	EN 573-3, EN 1301
	20 °C	2.11e-05 1/K	H18	EN 573-3, EN 1301
	20 °C	2.2899999999999998e-05 1/K	H18	EN 573-3, EN 1301
	20 °C	2.3199999999999998e-05 1/K	H18	EN 573-3, EN 1301
	20 °C	2.38e-05 1/K	H18	EN 573-3, EN 1301
	20 °C	2.4699999999999997e-05 1/K	H18	EN 573-3, EN 1301
	100 °C	2.2899999999999998e-05 1/K	H18	EN 573-3, EN 1301
	100 °C	2.3199999999999998e-05 1/K	H18	EN 573-3, EN 1301
	200 °C	2.38e-05 1/K	H18	EN 573-3, EN 1301
	300 °C	2.4699999999999997e-05 1/K	H18	EN 573-3, EN 1301
Melting point		505.0 - 640.0 °C	H18	EN 573-3, EN 1301
		505.0 - 635.0 °C	H18	EN 573-3, EN 1301
Specific heat capacity		875.0 J/(kg·K)	H18	EN 573-3, EN 1301
Thermal conductivity		121.0 - 193.0 W/(m·K)	H18	EN 573-3, EN 1301
		130.0 - 150.0 W/(m·K)	H18	EN 573-3, EN 1301

Electrical

Property	Value	Condition	Related Standards
Electrical conductivity	17000000.0 - 29000000.0 S/m	H18	EN 573-3, EN 1301
	18000000.0 - 21000000.0 S/m	H18	EN 573-3, EN 1301
Electrical resistivity	3.45e-08 - 5.88e-08 Ω·m	H18	EN 573-3, EN 1301
	4.76e-08 - 5.56e-08 Ω·m	H18	EN 573-3, EN 1301

Chemical properties

Property	Value	Condition	Related Standards
Chromium	0.1 %	H18	EN 573-3, EN 1301
Copper	3.8 - 4.9 %	H18	EN 573-3, EN 1301
Iron	0.50 %	H18	EN 573-3, EN 1301
Magnesium	1.2 - 1.8 %	H18	EN 573-3, EN 1301
Manganese	0.3 - 0.9 %	H18	EN 573-3, EN 1301
Silicon	0.5 %	H18	EN 573-3, EN 1301
Titanium	0.15 %	H18	EN 573-3, EN 1301
Zinc	0.25 %	H18	EN 573-3, EN 1301

Technological properties

Property
Anodizing	decorative: not suitable, Protective: good
Brazing	hard brazing (with flux/ without flux): not suitable / not suitable, friction soldering: acceptable, soft brazing with flux: not suitable
Corrosion properties	Seawater: poor, weathering: poor
Workability	Bending / Spinning (cold): sufficient (O) / acceptable (O), Impact extrusion (cold): acceptable (O), Deep drawing / upsetting (Condition) acceptable (O) / sufficient (O)

EN 573-3 Grade 3.1355 F Aluminum Alloy – Aircraft-Grade Strength & Machinability EN 573-3 Grade 3.1355 O3 Aluminum Alloy – Aircraft‑Grade Strength & Machinability

Metal