TUNNEL THROUGH PIN

Hawke's Bay Tribune, Volume XXV, Issue 64, 27 February 1935, Page 7

TUNNEL THROUGH PIN

How a Bet Was Won WATCHMAKER’S ARTISTRY In these days of mass production it is refreshing to find now and again that there are still individual craftsmen left who possess that fine sense of artistry which, in former years, gave distinction to British products throughout the world, says the News of the World. One of these modern industrial “Stars’’ is a Yorkshireman who has just accomplished something that is probbly a minor wonder of the world. The man cancerned is Mr Sydney Thomas Keyworth, a watchmaker, of Sheffield, and the remarkable feat he has performed is the boring of a hole from end to end of an ordinary pin. So perfect is the “tunnelling’’ ot the pin that Mr Keyworth, in the presence of the writer, passed a long piece of thin wire straight through it Hom end to end. Quito frankly he admitted, however, that he is not the first man to bore a “tunnel” through a pin. ft has been done once before by a Swiss tradesman, but with a shorter pin. “What prompted me to try one better than tho Swiss tradesman,” said Mr Keyworth, “was a discussion on the subject among a number of my friends. They offered to bet ‘drinks all round’ that 1 would never get a drill to do the job, or that I would ‘burst’ the pin when about half waythrough. “The size used by the Swiss was 1 l-16in., which is the standard length of the domestic pin. I chose one measuring 1 3-Bin.—s-16thin longer I took an all-British steel needle from a sew-ing-machine, and ground it down on a grindstone as a drill. This was really a more difficult operation than the actual boring. After grinding it down it had to be filed and fluted to a triangular end with one cutting edge. “My next obstacle was to set the pin in the ‘chuck’ so that the point of the drill would touch the dead centre of the pin-head. It meant working to a diameter of a five-thousandth part of an inch. It took some ‘fiddling’ about to find this exact point of contact before setting the drill in motion at the rate of lODO revolutions a minute, “When about half way through 1 stopped and took the pin out of the ‘chuck.’ It was so clogged with cuttings and so hot with friction that another few turns of the drill would have ruined everything. I then nipped off the point of the pin and resumed boring from that end toward the head. “Approaching the half-way mark again was not so risky as the first time, for the top half being already hollowed out, there was much less resistance to the drill. The barrier in the middle simply fell away—and the beit was won.” In his spare time Mr Keyworth loves trying to do all sorts of delicate jobs that even Job himself would have been unwilling to attempt.