A method of manufacturing a well tool can include loading a matrix material into a mold, then sintering the matrix material in the mold; and then loading another matrix material into the mold. A well tool can include a longitudinal axis, an erosion resistant layer exposed to one or more erosive factors when the well tool is installed in a well, and a support layer which supports the erosion resistant layer. The erosion resistant and support layers can include respective matrix materials, and the erosion resistant layer can extend greater than approximately 1.27 cm in a direction parallel to the longitudinal axis. Another method of manufacturing a well tool can include forming a rigid layer from a powdered matrix material; and then infiltrating both that matrix material and another matrix material with a hot liquid binder material.

A method of manufacturing a well tool can include loading a matrix material into a mold, then sintering the matrix material in the mold; and then loading another matrix material into the mold. A well tool can include a longitudinal axis, an erosion resistant layer exposed to one or more erosive factors when the well tool is installed in a well, and a support layer which supports the erosion resistant layer. The erosion resistant and support layers can include respective matrix materials, and the erosion resistant layer can extend greater than approximately 1.27 cm in a direction parallel to the longitudinal axis. Another method of manufacturing a well tool can include forming a rigid layer from a powdered matrix material; and then infiltrating both that matrix material and another matrix material with a hot liquid binder material.

A method for manufacturing a roof-bolt drill bit includes providing a bit body rotatable about a rotational axis in a rotational direction, the rotational axis extending between a forward end and a rearward end of the bit body, the bit body comprising a mounting region for mounting at least one cutting element to the bit body. The method includes forming at least one primary debris channel in the bit body, the at least one primary debris channel extending from adjacent the mounting region to a portion of the bit body located axially rearward from the mounting region, and forming at least one secondary debris channel in the bit body by machining a portion of the bit body along a substantially straight path to form an intersection with the primary debris channel.

A method for manufacturing a roof-bolt drill bit includes providing a bit body rotatable about a rotational axis in a rotational direction, the rotational axis extending between a forward end and a rearward end of the bit body, the bit body comprising a mounting region for mounting at least one cutting element to the bit body. The method includes forming at least one primary debris channel in the bit body, the at least one primary debris channel extending from adjacent the mounting region to a portion of the bit body located axially rearward from the mounting region, and forming at least one secondary debris channel in the bit body by machining a portion of the bit body along a substantially straight path to form an intersection with the primary debris channel.

A tip for twist drill, comprising a super-hard structure joined to a substrate at an interface boundary coterminous with an end of the substrate, the super-hard structure comprising sintered polycrystalline material comprising super-hard grains, the super-hard structure defining a super-hard end surface opposite the interface boundary and a plurality of cutting edges configured for boring into a body in use; the super-hard end surface including a center point or chisel edge, and comprising a plurality of surface regions configured such that respective planes tangential to each of the surface regions are disposed at substantially different angles from the axis of rotation of the tip in use. Precursor constructions for use in manufacturing the tips as well as methods for making the precursor constructions and the tips are disclosed.

A tip for twist drill, comprising a super-hard structure joined to a substrate at an interface boundary coterminous with an end of the substrate, the super-hard structure comprising sintered polycrystalline material comprising super-hard grains, the super-hard structure defining a super-hard end surface opposite the interface boundary and a plurality of cutting edges configured for boring into a body in use; the super-hard end surface including a center point or chisel edge, and comprising a plurality of surface regions configured such that respective planes tangential to each of the surface regions are disposed at substantially different angles from the axis of rotation of the tip in use. Precursor constructions for use in manufacturing the tips as well as methods for making the precursor constructions and the tips are disclosed.

The shank (12) of a disposable rotary cutting tool (10) comprises a pipe section (16) cut from a drawn metal pipe. The tool head (14) is formed from a cut-out (18a, 18b) of a drawn metal sheet or a section of a metal tube by non-cutting machining. The pipe section (16) and the tool head (14) are advantageously attached by force fitting.

The shank (12) of a disposable rotary cutting tool (10) comprises a pipe section (16) cut from a drawn metal pipe. The tool head (14) is formed from a cut-out (18a, 18b) of a drawn metal sheet or a section of a metal tube by non-cutting machining. The pipe section (16) and the tool head (14) are advantageously attached by force fitting.

The cutting tool (1), especially drill or milling cutter, comprises a base (3) which extends in an axial direction (2) and has an outer shell (14) with at least one interior recess (18) that extends in the axial direction (2), a supporting structure (16) having at least one separating piece (26) which separates a plurality of recesses (18) from each other being formed in the supporting structure. The cutting tool (1) is particularly a solid hard-metal tool. The supporting structure (16) ensures an efficient use of material.

The cutting tool (1), especially drill or milling cutter, comprises a base (3) which extends in an axial direction (2) and has an outer shell (14) with at least one interior recess (18) that extends in the axial direction (2), a supporting structure (16) having at least one separating piece (26) which separates a plurality of recesses (18) from each other being formed in the supporting structure. The cutting tool (1) is particularly a solid hard-metal tool. The supporting structure (16) ensures an efficient use of material.