Standard Shapes

• Standard extruded aluminum shapes include flat rails, I-beams, hollow tubes and channels. Extruded aluminum can be formed into multi-chamber tubes. According to the book "Aluminum Structures," "extrusions can be produced up to 100 ft long, but 40 ft is generally the practical limit for extrusions shipped by truck." Aluminum rails can be welded together to create longer sections, or mechanically attached using screws and bolts.
  
  

Automotive Uses

• Aluminum rails are used in cars due to their light weight compared to steel. Hollow aluminum rails are assembled into car window sills, rocker panels and frame rail ends. Extruded aluminum rails are used in impact beams designed to collapse in a specific manner during a crash to absorb the force without collapsing into the passenger area. "Collision Repair and Refinishing" states "parts that are used for structural purposes are usually 50 percent thicker than those made of steel." Aluminum is not used in car bumpers, though extruded aluminum rails and plate can be added for decoration.
  
  

Window Frames

• Aluminum rails are commonly assembled into window frames.Jupiterimages/BananaStock/Getty Images
  
  Aluminum rails can be extruded to hold two and three panes of glass to create low-maintenance window frames. Aluminum rail window frames do not require maintenance, but can be painted. According to "Extrusion" by Klaus Siegert, "the use of suitable aluminum alloys such as AlMgSi0.5 and sometimes AlMgSi0.7 ensures that the building components are low maintenance compared with other window materials." Insulation is placed in the hollow areas to reduce heat loss and condensation.
  
  

Doors

• Extruded aluminum rails are connected to create roller shutter doors. The aluminum reduces its weight, allowing the door to be raised and lowered by a person or small motor. Rails are assembled into sectional doors. Sectional doors are pulled out of their housing to create a temporary and removable wall. Extruded aluminum rails can be used in doors with large window panels.
  
  

Material Standards

• Extruded aluminum bars, rods, wire, profiles and tubes fall under ASTM B221, regardless of the aluminum alloy used. ASTM B241 applies to a seamless extruded tube, which can be used in hand rails. ASTM B429 applies to extruded structural pipe and tube, which is only made from alloys 6061 and 6063. ASTM B308 applies to standard structural profiles which are made from 6061 aluminum alloy.