Tools, for example, fixed cutter drill bits, may be manufactured to include hard composite portions having reinforcing particles dispersed in a continuous binder phase and auxiliary portions that are more machinable than the hard composite portions. For example, a tool may include a hard composite portion having a machinability rating 0.2 or less; and an auxiliary portion having a machinability rating of 0.6 or greater in contact with the hard composite portion. The boundary or interface between the hard composite portion and the auxiliary portion may be designed so that upon removal of the most or all of the auxiliary portion the resultant tool has a desired geometry without having to machine the hard composite portion.

A method for producing a cylindrical hollow body (20) made of aluminum, an aluminum alloy, or a light metal alloy, includes casting a hollow body (20) such that the hollow body (20) has an inner and an outer lateral surface (21, 22) and two axial end faces. The method also includes, during the casting process, making at least one defined notch (35, 35′) into one or more of the inner lateral surface (21), the outer lateral surface (22), and the two axial end faces.

A housing block includes channels formed in an interior of the housing block with at least one of the channels having a slot or flat-channel geometry at least in portions. A method is disclosed for producing the housing block. A sand core is disclosed to be used with the method for producing the housing block.

Provided is a multicore. The multicore includes a first core, being made of a water-insoluble material, having a hollow formed in the first core and, having an opening formed at both ends of the first core and connected to the hollow, a second core, being made of a water-soluble material and disposed inside the hollow, and a coating layer, being configured to surround the first core to prevent at least a portion of the first core and the second core from being exposed to an outside. Further, the first core includes a plurality of spaces to allow a fluid supplied to an interior of the first core to flow toward the second core.

Provided is a multicore. The multicore includes a first core, being made of a water-insoluble material, having a hollow formed in the first core and, having an opening formed at both ends of the first core and connected to the hollow, a second core, being made of a water-soluble material and disposed inside the hollow, and a coating layer, being configured to surround the first core to prevent at least a portion of the first core and the second core from being exposed to an outside. Further, the first core includes a plurality of spaces to allow a fluid supplied to an interior of the first core to flow toward the second core.

A gear includes an inner hub formed of metal material, the inner hub having an outer surface defining a plurality of outer teeth. The gear also includes an outer ring formed of non-metal material, the outer ring having an inner diameter that is smooth. The outer ring is disposed in an interference fit with the outer teeth of the inner hub.

A gear includes an inner hub formed of metal material, the inner hub having an outer surface defining a plurality of outer teeth. The gear also includes an outer ring formed of non-metal material, the outer ring having an inner diameter that is smooth. The outer ring is disposed in an interference fit with the outer teeth of the inner hub.

Provided are a method for producing a tire vulcanization mold and a maintenance method. A positioning member protrudes at a position corresponding to a position on a master mold surface. A positioning hole is formed by a tip end of the positioning member in a rubber mold to which the surface of the master mold is transferred. The tip end is embedded in the positioning hole so that a rear end protrudes from the surface of the rubber mold. The rear end is embedded in a plaster mold to which the surface of the rubber mold is transferred. A case is detachably fixed to the tip end protruding from the surface of the plaster mold. The case is cast into a mold to which the surface of the plaster mold is transferred and fixed. A valve body is inserted into the case from which the positioning member is removed.

Provided are a method for producing a tire vulcanization mold and a maintenance method. A positioning member protrudes at a position corresponding to a position on a master mold surface. A positioning hole is formed by a tip end of the positioning member in a rubber mold to which the surface of the master mold is transferred. The tip end is embedded in the positioning hole so that a rear end protrudes from the surface of the rubber mold. The rear end is embedded in a plaster mold to which the surface of the rubber mold is transferred. A case is detachably fixed to the tip end protruding from the surface of the plaster mold. The case is cast into a mold to which the surface of the plaster mold is transferred and fixed. A valve body is inserted into the case from which the positioning member is removed.

A surgical retractor for illuminating a surgical field includes an ergonomic handle, a retractor blade coupled with the handle, a quick release mechanism, and an illuminator blade. The retractor blade is adapted to engage and retract tissue, and the quick release mechanism is adapted to couple the handle with the retractor blade. The illuminator blade acts as a waveguide to transmit light by total internal reflection. Light is extracted from the illuminator to illuminate the surgical field. The retractor blade is releasable from the handle without requiring uncoupling of the illuminator blade from the handle and also without requiring optical uncoupling of the illuminator blade from a light source. The retractor may also be adapted to evacuate smoke from the surgical field.