Aluminium AlCuMgPb: properties, machining, applications

The aluminium alloy AlCuMgPb, known by the material number EN AW-2007, is one of the most important alloys for machining on an industrial scale. It offers a combination of high mechanical strength, very good machinability and dimensional accuracy, which is why it is indispensable above all in the series production of precision parts. It is a sought-after choice especially in automation technology, in mechanical engineering and for components with tight tolerance specifications.

Material profile of aluminium AlCuMgPb (EN AW-2007)

EN AW-2007 belongs to the group of aluminium-copper-magnesium-lead alloys and contains deliberately added lead to improve the machining properties. The material is offered primarily as a semi-finished product for mechanical machining.

Chemical composition (typical):

• Copper (Cu): approx. 4.0–5.0 %
• Magnesium (Mg): approx. 0.4–1.0 %
• Lead (Pb): approx. 0.2–0.8 %

Further constituents are small proportions of iron, silicon, manganese, zinc as well as the base metal aluminium. The combination of these elements produces an alloy with high strength and very good machinability.

Standard designations:

• EN 573-3 (alloy designation)
• EN 755-2 (mechanical properties)
• EN 485 (lead-containing flat products)
• DIN 3.1645 (historical)

Since the alloy is not suitable for welding and has low resistance to corrosive media, it is preferably used in closed, dry environments or with additional corrosion protection.

Mechanical properties and strength

Depending on the delivery condition, the strength varies considerably. In the T6 condition – the most common variant for automatic machining – high strength values are achieved together with good dimensional stability.

Typical mechanical values (T6):

• Tensile strength: approx. 390–470 MPa
• Yield strength: approx. 320 MPa
• Brinell hardness: approx. 120 HB
• Modulus of elasticity: approx. 72,000 MPa
• Density: 2.85 g/cm³

These values make EN AW-2007 a preferred material for components with high dynamic or static loading where short machining times and tight dimensional tolerances are required.

Advantages & limits of the alloy

Advantages:

• Excellent machinability with short chips and high dimensional accuracy
• High strength at comparatively low weight
• Very good suitability for mass production on CNC and automatic lathes

Limits:

• Limited corrosion resistance without surface treatment
• Not suitable for welding
• Limited anodising capability – decorative applications hardly possible

Machining and workability of AlCuMgPb

EN AW-2007 is designed specifically for the requirements of machining production. The lead-containing alloy composition produces short, well-breaking chips that reduce tool wear and improve machine running. This has a particularly economic effect in series production.

Machining tips:

• Carbide or coated tools for long tool lives
• High cutting speeds possible
• Sufficient cooling for chip removal recommended

On automatic lathes and turning centres, very high unit volumes can be produced economically with this alloy. Complex geometries can also be realised reliably thanks to the high dimensional accuracy.

Typical fields of application in industry

The main areas of application are those where repeat accuracy, dimensional accuracy and machinability matter. These include:

• Automation technology: precision sleeves, plug connections, carrier parts
• Mechanical engineering: shafts, bushes, mounts, milled parts with tolerance requirements
• Vehicle technology: connecting elements, functional components without corrosion exposure
• Electromechanics: turned parts for plug contacts, housing parts

The combination of strength, machinability and low density makes EN AW-2007 an economical solution for medium to high requirements.

Differences from comparable alloys (e.g. EN AW-2011, 2030)

Compared with EN AW-2011, 2007 has higher strength, but at the expense of machinability. EN AW-2030 is similar in many properties, but has a higher lead content and is used less frequently.

Alloy	Machinability	Strength	Corrosion resistance	Weldability
EN AW-2007	very good	high	low	no
EN AW-2011	excellent	medium	low	no
EN AW-2030	very good	high	low	no

Conclusion: 2007 is better suited to load-bearing components, while 2011 is preferred when extremely high machining speed and the best surfaces are the priority.

Delivery forms & availability

AlCuMgPb is available in a wide variety of semi-finished products. Particularly common are:

• Round material in diameters from 5 mm to over 200 mm
• Hexagonal bars for screw machines
• Sheet material for special milled parts
• Cut-to-size parts to measure (sawing, milling)

The good availability and the possibility of custom manufacturing make EN AW-2007 interesting for short-notice production orders too. Stockholding in the common dimensions is standard at specialised suppliers.

Conclusion: When is aluminium 2007 the right choice?

The aluminium alloy EN AW-2007 offers a strong combination of machinability, strength and dimensional stability. It is ideal for companies that want to manufacture precise turned and milled parts economically in high unit volumes. Especially for small to medium-sized components with tight tolerances, 2007 is the first choice – provided corrosion protection and weldability are not a priority.

Particularly suitable for:

• Machining on CNC automatic lathes
• High-precision turned and milled parts
• Series parts with tight dimensional tolerances
• Applications without welding or corrosion requirements