Couch block's corner relief matches modern machining practice, Dunn finds

October 09, 2026EgyptArtifactShare

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Key facts

• Couch blocks are contoured granite pieces found south of the eroded remains of the Pyramid (Mortuary) Temple at the eastern end of the Great Causeway, near a so-called boat pit.
• The block has a seat, two arms and a back rest, and is broken into two pieces with one arm lying beside the main piece.
• The presenter speculates the couch block may have been installed over a doorway or opening, since it has a beginning and an end rather than being a continuous cornice.
• Dunn used a precision straight edge on the axial surface of the contour and a wire radius gauge, finding the seat contour extremely consistent with no light showing through; the only deviation was a crack.
• Dunn measured the transitional blend radius between the seat profile and the vertical arms and back as 0.437 inch (11.112 mm), consistent by comparative measure all around using pressed forming wax.
• Dunn found a corner relief cut on the side blend radius, a technique that lets a mating part with a small radius butt against a larger blend radius and permits a larger, more rigid cutting tool.
• Dunn argued the block required a minimum of three axes of movement (X, Y, Z) to machine and would be beyond simple handwork.
• The presenter claims this corner relief is hard evidence for sophisticated ancient machining.

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