A drill bit includes a shank, an intermediate portion with a helical flute, and a multi-stepped tip portion extending along the axis. The tip portion includes a cutting tip with a pair of primary cutting edges extending radially outward from the axis, a plurality of steps each having an elongated portion and a tapered portion tapered outward from the elongated portion relative to the axis. The elongated portions progressively increase in diameter from the cutting tip to the intermediate portion. The elongated portion of each step has an axial relief tapered inward toward the axis. A frontmost elongated portion has a first axial relief at a first angle relative to the central axis and a rearmost elongated portion has a second axial relief at a second angle greater than the first angle. The drill bit may be used as a pilot bit together with a holesaw in a system.

A step drill bit includes a cutting head portion with a rear end coupled to a shank portion. The cutting head portion incudes a front cutting tip, a plurality of steps of progressively increasing diameter from the cutting head to the rear end portion. Each step includes a conical tapered portion that flares radially outward from the axis and a generally cylindrical portion that extends axially rearward from the tapered portion. A flute extends through the steps generally parallel to or helically relative to the axis. Primary and secondary cutting edges are formed at junctions between the tapered portions and the generally cylindrical portions and the flute. A depth stop flange extends radially outward from a rearmost step and has a diameter greater than the diameter of the cylindrical portion of the rearmost step. A deburring recess is disposed within or between one of the steps and includes a deburring edge at a junction between the deburring recess and the flute to remove burrs from an edge of a hole.

A rotary tool according to a non-limiting aspect has a body that has a rod shape extending from a first end to a second end and is rotatable about a central axis. The body has a first cutting edge positioned on the first end, a first flute extending from the first cutting edge toward the second end, a second cutting edge being on a side of the second end and on a side of an outer periphery with respect to the first cutting edge and being positioned away from the first cutting edge, and a second flute, extending from the second cutting edge toward the second end and being positioned along the first flute. The second flute has a projecting portion extending from a side of the first end toward a side of the second end.

A method produces a housing of a rotary screw compressor, the housing having at least one housing body and at least one housing cover. The method includes the following steps: bearing seats for at least one screw rotor of the rotary screw compressor are provided in the housing body and in the housing cover; at least one screw borehole for the at least one screw rotor of the rotary screw compressor is provided in the housing body; the housing body and the housing cover are temporarily assembled using at least one alignment tool for ensuring the alignment of the screw rotor central axis with the central axes of the bearing seats and the screw borehole; and at least one bolt insertion opening is provided in both the housing body and the housing cover by at least one common production process.

A method produces at least one first screw bearing seat and at least one first inner wall region in a rotor housing. The rotor housing is part of a housing of a screw compressor. The method orients the rotor housing of the screw compressor, and produces the first screw bearing seat and the first inner wall region of the rotor housing in at least one joint production operation.

A cutting tool and method of manufacturing a tool including determining desired flowrates to cutting edges. The method includes calculating pressure drop and passage dimensions for each of an nth-number of passages to the cutting edges based on I.sub.n=(P.sub.n*A.sub.n.sup.n)/(.sub.n*L.sub.n), wherein I.sub.n is nth-passage flow rate, P.sub.n is nth-passage pressure drop, A.sub.n.sup.n is nth-passage cross-sectional area raised to a power n, the power n being equal to 1 or 0.5, .sub.n is nth-passage resistivity, and L.sub.n is nth-passage length. The method includes forming the nth-passages in the tool open to each cutting edge based on the nth-passage dimensions.

A drill bit includes a shank extending along a bit axis and a body with a proximal end adjacent the shank and a distal end opposite the proximal end. The body defines a plurality of axially stacked, progressively sized steps including a first step at the distal end and a terminal step at the proximal end. The drill bit also includes a flute in the body. The flute defines an elongated groove that extends from the distal end to the proximal end. The drill bit further includes a plurality of cutting edges formed in the body. Each cutting edge is disposed along one of the plurality of steps and defines a helix angle and a rake angle. The helix angle of the cutting edge at the terminal step is greater than the helix angle of the cutting edge at the first step. A ratio of the helix angle to the rake angle of the cutting edge at the first step is in a range from 0.5 to 2.4, and a ratio of the helix angle to the rake angle of the cutting edge at the terminal step is in a range of 0.9 to 1.7.

A pocket hole jig system is formed of a plurality of jig segments, wherein each jig segment includes a main body having a drill guide and a lock feature that protrudes outward on a first side of the main body and a recess that protrudes inward on a second side of the main body. The system also includes one or more spacers that have a main body of varying width and a lock feature that protrudes outward on a first side of the main body and a recess that protrudes inward on a second side of the main body. Jig segments and spacers may be connected together by inserting the lock feature of a jig segment or spacer into the recess of an adjacent jig segment or spacer. In one arrangement opposing jig segments and/or spacers lock together with a combination of rotational movement as well as sliding movement.

An accessory tool includes an adapter end having a maximum outer dimension, and a shank coupled to the adapter end. The shank includes a tool engagement portion including a cross section having a maximum outer width, a first reduced portion disposed between the tool engagement portion and the adapter end and having a first minimum outer dimension and a first length, and a second reduced portion formed in the tool engagement portion between the first reduced portion and an end of the shank. The second reduced portion is engaged by the tool to secure the shank to the tool, and has a second minimum outer dimension and a second length. The maximum outer dimension is greater than the maximum outer width. The maximum outer width is greater than the first minimum outer dimension and greater the second minimum outer dimension. The first length is greater than the second length.

A device for opening a connection to a lined pipe is disclosed. The device has a body that includes a front end and a rear end and being rotatable about a rotation axis. The device also has a drill head that has multiple cutters for puncturing and enlarging a hole in a liner, and multiple side cutters have at least one cutting edge parallel to the rotation axis. A safety ring is disposed on the body between the drill head and the side cutters. The safety ring has a circular periphery extending beyond the drill head and the side cutters in a direction perpendicular to the rotation axis.