5251

Grade 5251 is a medium strength non-heat treatable aluminium alloy. With additions of magnesium, iron and manganese the material offers a high corrosion resistance in marine, offshore and industrial environments coupled with a medium strength level.

Grade 5251 is traditionally recognised as a general sheet metal working grade. It is readily weldable and offers higher mechanical properties together with a good cold formability. However, Alloy 5251 is known for work hardening rapidly so care needs to be taken during the forming process.

Chemical Composition

Aluminium	Rem	Silicon	0.4% max
Copper	0.15% max	Iron	0.5% max
Manganese	0.1–0.5%	Magnesium	1.7-2.4%
Zinc	0.15% max	Titanium	0.15% max
Chromium	0.15% max	Total Others	0.15% max

Related Specifications

5251	Al Mg2	Al 2.0Mg 0.3Mn
NS4	EN AW 5251

Key Features

Very good cold formability
Readily weldable
High marine corrosion resistance
Good aesthetic properties
Very good anodising properties

Typical Physical Properties

Melting Range	595-650°C
Density	2.69 g/cm³
Thermal conductivity	155 W/m°K
Thermal expansion coefficient	24 x 10^-6
Electrical Conductivity	36.7 IACS
Electrical resistivity	0.047 microhm m
Modulus of elasticity	70 GPa

Fabrication Properties

Cold Formability	Very Good
Machinability	Average
Brazing and Soldering	Poor
Inert Gas Welding	Very Good
Resistance Welding	Very Good

Typical Applications

Grade 5251 has typically been used in boats, panelling and pressings, offshore marine structures aircraft parts, vehicle panels, furniture tubing, silos, containers.

This technical information is given by Holme Dodsworth Metals without charge and the user shall employ such information at their own discretion and risk. For more detailed technical advice on temper selection, fabrication, joining, machining, physical and mechanical data please contact us as space does not permit the listing of every feature of the material.