Aluminum 6061 AMS 4173

AMS 4173 is the aerospace material specification covering 6061 aluminum extrusions in the T6511 temper: solution heat treated, stress relieved by stretching, straightened and precipitation heat treated.

What defines AMS 4173 is the stretch-and-straighten step. After quenching, each extrusion is stretched to relieve residual stress and then given minor straightening. The result is a bar that stays straight and true when you cut deep pockets, slots or long profiles into it. That’s why T6511 extruded bar is the standard feedstock for machined aerospace parts and is the most commonly stocked 6061 extrusion. It’s usually dual certified to ASTM B221.

Typical uses for AMS 4173 include:

• CNC-machined fittings, brackets and housings from extruded bar
• Long machined rails, beams and stiffeners
• Square and rectangular bar for precision components

For extrusions used close to their extruded shape without heavy machining, see the companion specification AMS 4150. Full chemical composition and mechanical properties are on the 6061 aluminum page. Tech Steel & Materials stocks and supplies AMS 4173 extruded bar to aerospace and defense tolerances. Request a quote for certified material cut to your size and quantity.