An Alloy is the resulting compound that is produced when other elements are added to aluminum. Alloyed aluminum is one of the most versatile and cost effective engineering and construction materials available.


Commercial purity of aluminum is 99.5 to 99.79%, but pure aluminum is too soft to be of structural value. The primary reason for alloying aluminum is to increase strength without significantly increasing weight. Other reasons are to improve machinability, weldability, surface appearance and corrosion resistance. 

Each alloy type has specific characteristics to match application needs as described in the table below. Penn extrudes the 3xxx series and 6xxx series alloys.

Wrought Alloy
Major Alloying Elements and
Typical Alloy Characteristics
Typical Alloy

3xxx Series

Manganese ...
Low to medium strength; good corrosion resistance; poor machinability; good workability; strain-hardened.
Drawn tubing in the form of heat exchangers, chemical equipment, furniture,  condensers, builder's hardware, cooking utensils, medical applications.

6xxx Series

Magnesium & Silicon ...
Most popular extrusion alloy class. Good extrudability, strength, corrosion resistance, machinability, weldability; formability. Heat-treatable.
General purpose extruded shapes such as architectural applications,  heavy-duty structures, pipe and tubing.

Product performance is determined in part by the alloy composition and in part by the method of production. The production method, in turn, strongly influences the final temper of the alloy, which is obtained through various types of mechanical and thermal treatments. The choice of alloy and temper significantly influences structural and certain physical properties of aluminum.