A cutting body for a drilling tool has a center axis, at least one cutting element with at least one cutting edge, and at least one side face. The at least one side face has at least one radially inwardly directed cutout, which is designed to produce a drilled hole having an increased roughness, the cutout having precisely three open sides.

A liquid container for producing and/or storing liquids, in particular alcohol-containing liquids, intended for consumption comprises a container that is open at one end, can be closed by a lid and container walls with an inner wall surface that is at least partially, in particular substantially entirely, in the form of a surface of a solid natural stone. Also described are various methods for producing such liquid containers and a method for producing and/or storing drinkable liquids using such containers.

A method for producing a twist drill has the following steps. A blank is shaped to form a semi-finished product. The semi-finished product is formed from a core, coaxial with the drill axis, having a radius and a number of webs, arranged on the core, having a height. The semi-finished product has a constant cross section along the drill axis. The webs have a first portion which adjoins the core and in which a width of the web remains constant or decreases in the circumferential direction with increasing radial distance from the drill axis. The webs have a second portion which adjoins the first portion and in which the width of the web increases in the circumferential direction with increasing radial distance from the drill axis. The webs of the semi-finished product are shaped into helical segments using a plurality of rolling tools that annularly enclose the semi-finished product and roll on the webs along the drill axis. The rolling tools have teeth that are inclined with respect to the drill axis. A height of the helical segments is less than the height the webs. Helical segments formed from adjacent webs are in contact with one another in a closing fold. The invention also relates to a twist drill.

This invention affords the power drill operator the ability to adjust the flow of water to maximize the cooling and cleaning effect upon the diamond drill bit being used, and after it is set upon the tile surface, no other adjustments are needed, allowing the operator greater safety and precision in using the drill with both hands while greatly extending the life of the expensive diamond studded drill bit.

A diameter expansion drill bit used to expand the diameter of a part of a prepared hole bored in a frame by grinding includes: a cutting-blade portion that has a plurality of separate cutting-blade portions; a cutting-blade holding portion that slidably holds the plurality of separate cutting-blade portions in a radial direction; and a shank portion that supports the cutting-blade holding portion. The plurality of separate cutting-blade portions is arranged in a peripheral direction and arranged over a plurality of stages in a shaft direction, and the plurality of separate cutting-blade portions of the respective stages is caused to slide by a centrifugal force resulting from rotation so as to spread to an outside in the radial direction with respect to the cutting-blade holding portion.

A guide device comprising a hollow body configured to receive a drill bit, the hollow body having a first end; a second end; and a continuous section intermediate the first end and the second end; an opening extending from the first end through the continuous section to the second end; and at least one aperture located on the hollow body intermediate the first and second end of the hollow body.

A method for operating a machine tool that includes an electric motor for driving a drilling tool and an open- and closed-loop controller for open- and closed loop control of the motor power. The method includes: operating the machine tool in a tapping mode at a first rotational speed value, where the first rotational speed value is lower than a predetermined idling speed value of the electric motor; detecting a predetermined first threshold value for the motor current; reducing the motor current to a predetermined second threshold value when the first threshold value is exceeded; operating the machine tool at a second rotational speed value, where the second rotational speed value is lower than the first rotational speed value; operating the electric motor at a predetermined motor current value; and operating the controller for closed loop control of the motor power via the motor current with an oscillating action.

A method for producing a drill includes cold forming of a rod-shaped blank to form a semifinished product having three or more rectilinear longitudinal ribs extending along a longitudinal axis of the semifinished product, introducing the longitudinal ribs into a first die and a second die in a working direction, where the first die bears against the longitudinal ribs in a direction of rotation about the longitudinal axis and the second die bears against the longitudinal ribs counter to the direction of rotation, pivoting the first die in the direction of rotation in relation to the second die in order to twist the longitudinal ribs between the first and second dies, pulling the longitudinal ribs 31 through the pivoted first die and the second die counter to the working direction in order to twist the longitudinal ribs and apply a drill head to the rear end in the working direction.

A wood-drill adapter system having a wood-drill adapter assembly. The wood-drill adapter assembly includes a core-bit-blank, an adapter-insert, and a set-screw. The core-bit-blank includes a hollow-tubular body, with the hollow-tubular-body including a hole; and the cap includes a cap-plate, and a threaded-coupler. The wood-drill adapter assembly is useful for allowing a user to use a coring-rotary-tool typically used for concrete drilling/coring to drill a circular-opening in a wooden-material using the wood-boring tool. The adapter-insert includes an upper-disc, a tubular-body, a lower-disc, and a set-screw-receiver. The upper-disc includes an upper-face, a lower-face, an outer-circumference, and an upper-aperture. The lower-disc includes an upper-surface, a lower-surface, an external-circumference, and an internal-circumference. The tubular-body includes an outside-circumference, an inside-circumference, an upper-rim, and a lower-rim.

A one-piece cutting head for a drill bit includes a main cutting edge that extends between radial extremities of the cutting head. The main cutting edge is disposed between main rake surfaces and main relief surfaces. Each main rake surface includes one or more rake facets, and each main relief surface includes one or more relief facets. Adjacent rake facets and relief facets define a primary transverse edge therebetween that extends away from the main cutting edge. The cutting head further includes a plurality of side cutters that are transverse to the main cutting edge and that propagate from the primary transverse edge to a radial extremity of the cutting head. Each side cutter includes a side cutting edge between a side cutting rake facet and a side cutting relief facet.