Thru joint for configurable backpack frame chair

A configurable frame system having a first configuration and a second configuration, comprising:

• a first U-shaped subframe with a first open end having a first pair of upright members connected to a first cross member to form a first closed section of the first U-shaped subframe;
• a second U-shaped subframe with a second open end having a second pair of upright members connected to a second cross member to form a second closed section of the second U-shaped subframe, wherein the second pair of upright members have a pair of connection holes through an entire width of each second pair of upright member such that a centerline of each connection hole intersects the centerline of the second pair of upright members;
• wherein the first and second pair of subframes are fully detachable and attachable from each other;
• wherein the first configuration is a backpack configuration when the first U-shaped subframe and the second U-shaped subframe are mechanically fastened such that both U-shaped subframes are connected coplanar in a fixed relation to one another;
• and
• wherein the second configuration is a chair configuration when the first U-shaped subframe and the second U-shaped subframe are mechanically fastened at a self-intersecting tubular joint, wherein distal ends of the first U-shaped subframe are inserted through the connection holes in the second U-shaped subframe.