American horological journal, devoted to practical horology (1869)
Miller, George B · New York, G. B. Miller · leaf 159
ce of steel wire, andturn down the end with a tit of just thesize of the hole in which it is intended to beentered. The shoulder, as a matter of course,should be perfectly true and square, and theoutside turned off to the accurate size of thehead of the screw that is to be put in; theworkman, in… … clearing portion of the tool will enable thechip to roll out of the hole without marringthe edges. This tool may be made in theform of a twist drill; that is, the cutting lipsmay be formed in the same manner, and thisgives, provided the groove is sharply under-cut, a means by which the chip may…
Clocks and watches
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