are slid out as a unit from the top of the housing on a side opposite from where a tap 50 projects as indicated in fig3 this allows convenient replacement of the tap 50 and also changing the pitch adapter plug 58 and sleeve 42 with only minimal effort and time required fig5 7 show a second embodiment of the invention in which the tap mounting assembly including a housing 64 which is configured to offset the tap 66 from the axis of a servo motor 68 the servo motor 68 has an output shaft 72 which has a pinion gear 74 affixed thereto driving an idler gear 76 which in turn drives a tap driver gear 78 affixed to a hub sleeve rotatably supported in the housing 64 the hub sleeve 80 is keyed to pitch adapter 82 having an externally threaded extension 84 threadably engaged with an internally threaded cover cap piece 86 detachably affixed to the housing 64 a tap holder sleeve 88 is slidably received in a bore in the pitch adapter 82 and slidably keyed thereto with a key 89 to be rotated when the pitch adapter 82 is rotated a snap ring 83 acts as an axial stop limiting axial movement of the tap holder sleeve 88 downwardly in the pitch adapter 82 as shown in fig7 under the urging of a safety spring 94 a taper grip collet 90 of a well known type threaded into an end bore 92 of the tap holder sleeve 88 is used to grip the tap 66 for retention therein upon being wrenched tight the tap holder sleeve 88 has a stepped outside diameter creating a shoulder.