I finally got through granite using a copper tube drill, abrasive sand, water, and patience.

In my first attempt at recreating an ancient Egyptian-style granite drill, the setup failed for several mechanical reasons. This time, I corrected the copper-to-wood connection, added notches to the copper edge, used a sand-and-water slurry, and tested whether copper and abrasive material (corundum, emery, bit of quartz) could actually cut red granite.

To be clear, I did use a modern drill press in this stage of the experiment. The goal here was not to perfectly recreate the entire ancient machine from start to finish, but to isolate one part of the problem: can a copper cutting edge, with abrasive sand and water, cut granite and produce a core? Once that question was answered, the next step will be to build a fully human-powered machine within the mechanical capabilities available to ancient Egyptians, only with better construction than last time

The result surprised me. Not only did it cut through the granite, but the core and grooves revealed something important about how abrasive slurry works, why drill cores taper, and why the famous “spiral” marks on ancient Egyptian drill cores may not require advanced machinery at all.

In this video, I compare my copper-and-sand core to a modern diamond-drilled core, examine the grooves under magnification, and explain why the taper may be one of the most overlooked clues in ancient Egyptian stone drilling. Thanks to @SacredGeometryDecoded for being a pioneer in practical tests of abrasive drilling. They have many more experimental archeology videos on their channel so go check them out.

Resources Used:

Drill Cores at the British Museum and Petrie Museum

https://www.britishmuseum.org/collection/term/x6559?id=x6559&page=1#page-top

https://collections.ucl.ac.uk/results

Petrie Core#7:

https://collections.ucl.ac.uk/Details/petrie/26868

Practical Experimentation results:

https://antropogenez.ru/drilling/

Tools and Weapons of Ancient Egypt by Flinders Petrie

#AncientEgypt #AncientEngineering #Egyptology