Abstract: A cylindrical rotating tool comprises a major diameter portion having formed therein an internal fluid passage, a minor diameter portion provided in front of the major diameter portion, and a tip attached to the front of the minor diameter portion. When seen from behind the central axis line, an inner circumference of an outlet of the internal fluid passage intersects with an outer circumference of the minor diameter portion. At the site of the outlet, a notch is formed on an outer circumferential surface of the minor diameter portion. An inclined portion of the notch is formed obliquely so that the distance from the central axis line to the inclined portion on further forward of the minor diameter portion becomes larger than the distance from the central axis line to the inclined portion on a closest position on the entire circumference of the outlet to the central axis line.

Abstract: Machine tool having a bed, a table arranged on the bed, a first saddle provided free to travel back and forth, a second saddle supported on the first saddle and provided free to travel side to side, a spindle head provided free to travel perpendicularly on the second saddle, a main spindle situated above the table and by the spindle head supported free to rotate on its center axis, a front cover provided on the front side of the bed and furnished with doors that open and close sideways, and top covers configured with one end sideways shiftably connected to the front side of the first saddle, and with another end connected extensibly/retractably to the top of the front-cover doors, therein being configured for permitting back-and-forth-directed movement of the first saddle.

Abstract: A numerical control apparatus (1 or 20) comprising pecking operation controlling means (12) which make a feed drive system (14) retracted when a cutting load detected by cutting load detecting means (7) exceeds a reference value during a drilling process, the cutting load detecting means (7) comprise a bite load detecting section (8) to detect the cutting load at a biting stage wherein a tool bites a work piece, and a stationary load detecting section (10) to detect the cutting load after the biting stage. The numerical control apparatus (1 or 20) comprises pecking judgement means (11) to judge that the feed drive system (14) should be retracted when a fluctuation load exceeds a specified reference value wherein the fluctuation load is obtained by reducing the bite load from the detected stationary load. When it is judged that the feed drive system (14) should be retracted, the pecking operation controlling means (12) make the feed drive system (14) retracted.