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KNOW THE DIFFERENCE BETWEEN A HOOKED REAMER AND A WHIMBLE BRACE

Low Tech magazine have produced another fascinating web page - this time on hand drills by Kris de Decker. Drilling, and the technology to do it, was probably a byproduct of making fire which used tools like the traditional bow drill or strap drill. The pump drill, a stone age version of a pump screwdriver was an advance on these which used a flywheel and only needed one hand to make it work. The thong drill worked on the same principle but needed three people to work it - one on the drill and two on each thong.

Experiments have shown that it was theoretically possible that the Egyptians could drill up to 12cms an hour into granite with 11cm bronze core bits and abrasives. Some historians believe this happened using several people and a large bow drill. The ancient Chinese also had multi-person thong drills which were used in shipbuilding.

Reamers and braces came in with advances in metalworking, although is took until the twentieth century for the geared hand drill to appear using cheap steel and interchangeable parts - something which I still use and is especially useful for running boat repairs.

ID : (56823)
Date Created : 16 December 2010 09:52:37 AM
Date Modified : 16 December 2010 09:52:41 AM


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