Your Guide to Material Selection

When it comes to material selection, it really comes down to your part’s function:

  • What is it going to do?
  • What mechanical properties are you looking for?
  • Will it be subjected to high stress or wear?
  • Will your part include fine details (like lettering or your company logo)?

This table outlines the cast aluminum alloy designation system:

Alloy Series

Principal Alloying Element

1xx.x

99.000% minimum aluminum

2xx.x

Copper

3xx.x

Silicon plus copper and/or magnesium

4xx.x

Silicon

5xx.x

Magnesium

6xx.x

Unused series

7xx.x

Zinc

8xx.x

Tin

9xx.x

Other elements

 

The second and third digits (xXX.x) are arbitrary numbers given to identify a specific alloy in the series. The number following the decimal point indicates whether the alloy is a casting (.0) or an ingot (.1 or .2). A capital letter prefix indicates a modification to a specific alloy.

COMMONLY USED ALLOYS IN OUR FACILITY

356.1 AND A356.2 GENERAL PURPOSE ALUMINUM

356.1 is a recycled material that is popular among a wide variety of products because of its desirable characteristics. While this aluminum is known for its high strength, its counterpart A356.2 (original material direct from smelter) contains improved mechanical properties. A356.2 offers more strength, ductility and elongation.

The trade off is typically A356.2 is more expensive than 356.1.

319.1  LEGACY GRADE ALUMINUM

Before cutting technology improved, 356 general grade aluminum would stick to cutting tools, which is why 319.1 was widely used. 319.1 has higher iron content, making it easier to machine, but the higher iron content leads to more shrinkage defects, which makes it more difficult to cast.

319.1 is not as common as it once was now that machining technology has advanced.