Slot structural framing is a framing system consisting of lengths of square or rectangular extruded aluminum, typically 6105-T5 aluminium alloy, with a T-slot down the centerline of one or more sides. It is also known as 80/20 framing, after the company 80/20, Inc., one of the prominent T slot framing brands, the name of which is based on the 80/20 principle.
While there is no published standard defining this framing system,
manufacturers have settled into two categories of product comprising several series each that is generally intercompatible across manufacturers.