Abstract: A tool bit for use in at least one of a drilling and cutting operation is formed of an axially extending carrier member (1) and a cutting member (2). The cutting member (2) has an expansion joint (2a) extending parallel to the axis of the carrier member (1). The expansion joint (2a) is formed by reducing the thickness of the cutting member (2) so that material webs (2b) remain. In the fabrication and formation of the tool bit, the cutting member (2) is a single unit. In the use of the tool bit, due to the expansion joint the cutting member forms individual operating units (2a) affording reduced material expense of the cutting member (2), because of reduced stresses.

Abstract: A material removing tool wherein a substantially plate-like support of steel carries at least one annular cutter which is made of a harder metallic material capable of being soldered to the material of the support. The support has a centrally extending projection which is received in a complementary opening of the cutter, and the cutter has two or more substantially radially extending webs in register with grooves which weaken the cutter in the regions of the webs so that at least one of the webs breaks in response to soldering of the cutter to the support. The breaking of one or more webs is promoted by proper selection of the thermal expansion coefficients of the materials of the support and cutter. The provision of breaks in the webs, either as a result of bonding or as a result of utilization of cutter sections, ensures that each cutter section between two neighboring webs can be put to use independently of the condition of the other section or sections.