Abstract: A Drilling tool for metallic materials comprises a holder (1) having an axial clamping slot in which a plate-shaped drilling blade (2) is inserted and clamped against a limb (8) of the clamping slot by means of a threaded pin (3), which is provided with a head (21) and which engages in a bore (15) in the drilling blade (2) and in a bore (12) in said limb (8). The center axis (13) of the limb bore (12) is offset relative to the center axis (24) of the drilling blade bore (15). The mutually facing circumferential edges of the head (21) of the threaded pin and the bore (15) of the drilling blade is bevelled. A centering pin (11) is inserted in the holder (1) and engages in a centering slot (18) in that side (17) of the drilling blade (2), which is contacting the base surface (9) of the clamping slot (4) to center the drilling blade (2) with respect to the rotational axis (6) of the holder (1).

Abstract: A one-piece rotary drill or end milling cutter is an extruded product made of sintered hard metal. The front end portion of its shank has one or more cutting edges and its rear end portion tapers in a direction away from the front end portion and is receivable with friction in a complementary conical socket of a rotary holder. The shank has one or more longitudinally extending coolant holes with a circular or triangular cross-sectional outline, and such hole or holes are formed in the course of the extruding step. The periperhal surface of the shank has one or more longitudinally extending chip evacuating grooves, and those portions of the grooves which are formed in the rear end portion of the shank contain fillers of bondable plastic material or solder.

Abstract: A single-lip solid drilling tool has a one-piece shank with an integral head having a radially or diametrically extending groove for a blade with an eccentric tip. The blade is held in its groove by several clamping screws so that it can be removed for sharpening or for replacement with a fresh blade. One or both lateral portions of the blade extend beyond the periphery of the head to guide the tool in actual use. The shank has an eccentric coolant hole whose discharge end is adjacent the blade and which is formed by providing a short cylindrical hard-metal blank with an eccentric axially parallel bore before the blank is stretched to reduce its diameter to a requisite value and to simultaneously reduce the diameter of the bore. The stretched blank is then machined to provide it with one or more chip evacuating flutes and, if necessary, with one or more grooves for discrete guide members which extend beyond the peripheral surface of the head.

Abstract: A material removing tool includes an elongated shank having a rear end portion arranged to be driven by the motor of a boring or milling machine and a front end portion provided with a coaxial stub which is received in a socket between two legs of an adapter which carries the cutting implement. At least one of the legs has a radial hole which is in near register with a tapped bore of the stub. The shank portion of a screw, whose head bears against a conical surface surrounding a portion of the hole in the one leg, meshes with the threads in the tapped bore of the stub to urge the rear edge faces of the legs against complementary surfaces provided on two shoulders forming part of the front end portion of the shank. This enhances the resistance to bending stresses and prevents wobbling or vibration of the adapter relative to the shank.

Abstract: A rotary material removing tool whose holder can be installed in and rotated by a milling or like machine. The front portion of the holder has a transverse slot flanked by two prongs and receiving a portion of a flat cutter which is held in the slot by one or more coupling screws in such a way that its rear surface is urged against the bottom surface in the slot. The coupling screw is received in a bore of one of the prongs and its head extends into a bore of the cutter. The peripheral surface of the head and/or the surface surrounding the corresponding portion of the bore in the cutter is conical, and the two surfaces cooperate to urge the rear surface of the cutter against the bottom surface in the slot when the screw is driven home. To this end, the axis of the bore which receives the shank of the screw is disposed between the axis of the bore in the cutter and the bottom surface in the slot.

Abstract: A spade drill is provided with a holder for a spade cutting blade which is clamped in a slot of the holder by means of a clamp screw. The spade cutting blade is essentially formed with a cutting surface coming to a central point and of the same shape as the first cutting surface with an abutment surface located within the spade drill holder in the clamping slot which receives the cutting surface for holding the bit in place with means in the form of a clamp located across the clamping slot to grip the spade drill bit.