Abstract: A rotary cutting tool has an axially moveable drill pilot supported in the forward end of an arbor. A first set screw connects the arbor to an annular hole cutter. A second set screw connects the arbor to the drill pilot. The drill pilot has an integral collar that engages the inner end of the hole cutter to prevent the drill pilot from being ejected from the arbor in the event that the second set screw is disengaged from the drill pilot.

Abstract: A portable electromagnetic drilling machine which is provided with an enclosed motor power control cord that connects the machine electrical control panel to a machine electric drive motor for a cutting tool spindle. The provision of an enclosed electric motor power control cord eliminates any wrongful or inadvertent lifting of the machine by said cord, and insures the lifting and carrying of the machine will be carried out by a handle on the machine housing.

Abstract: An annular hole cutter including a cylindrical body provided with a plurality of circumferentially spaced apart cutter teeth, including a first group of cutter teeth that have alternate radial inner cutting edges and a second group of cutter teeth that have alternate radial outer cutting edges that are staggered circumferentially rearwardly from the alternate radial inner cutting edges of the first group of cutter teeth. The cutting edges on the cutter teeth of both groups of cutter teeth each have a leading point, and the leading point of the cutting edges on one of said groups of cutter teeth extends downward longitudinally beyond the leading point of the cutting edges on the other of said groups of cutter teeth.

Abstract: An annular hole cutter having a shank and an integral cylindrical body provided with a plurality of axially extended cutting teeth which each has an inner cutting edge and an outer cutting edge. The inner and outer cutting edges are equal in radial width and their inner ends meet in a common leading cutter point. The outer and inner cutting edges on each cutting teeth share a substantially mutual radial face.

Abstract: A cradle type adaptor for a magnet base drill which includes a box having a width slightly smaller than the width of the magnet base of the drill so that it can be assembled to the magnetic base by a clamping action. The box includes a pair of longitudinal sides and a pair of end sides. A front and rear vertically adjustable plate is adjustably mounted on the front and rear sides of the box. The front and rear adjustable plates have a V-slot in the lower ends thereof. The lower end of each of the longitudinal sides of the box is formed at an oblique angle so that the adjustable side plates may be adjustably mounted thereon for mounting the cradle pipe adaptor on a small size diameter pipe.