Founded in 1951 by Marino D'Andrea, the D'Andrea company is still to the forefront in the supply of boring and facing heads and high precision toolholders. Based in XXX in Italy, Marino D'Adrea's invented and manufactured the world's first boring head where the cut could be adjusted by hand - or auto-feed engaged or disengaged - without stopping the milling, boring or drilling machine to which it was fitted. While on a lathe, as the required diameter of bore is approached, it is possible to adjust the cut in tiny increments until perfection is achieved, on a normal boring head this is not possible, and the machine must be stopped to adjust the cut. The movement of the tool was shown on simultaneously on two micrometer dials set at 90° to each other, one reading to 0.05" the other to 0.0005" on diameter.
Engaged by a lever, two continuous, automatic feed rates were provided of 0.0025" and 0.0075" per revolution with, as part of the standard specification, two adjustable stops and the drive incorporating a safety overload clutch. Early versions were listed as the T.S.1, TS2 and TSR3, first lacking a quick power tool-slide return mechanism but the latter pair fitted with it. Later models were redesigned to have a more "modern" appearance with the range expanding to four Models, the T100, TA120, TA170 and TA200 - their differing specifications being shown in the illustrations below. As might be expected, of all-steel construction, the component parts of the head were case hardened and ground finished on all working surfaces..