A drilling tool consisting of a drill shank having a drill point and of a transition section which adjoins the drill shank in the axial direction and which merges into a clamping shank, the transition section being heat-treated in such a way that it has higher bending elasticity compared with the clamping shank and/or the drill shank.
1. A method of producing a drilling tool of the type formed as a single integral piece comprising a transition section integrally formed between a drill shank and a clamping shank with the transition section being subjected to a heat treatment in such a way that it is given higher bending and torsional elasticity compared with the clamping shank and the drill shank within a region subjected to the heat treatment.
2. A drilling tool of the type having a drill shank with a drill point and a transition section which adjoins the drill shank in the axial direction and which merges into a clamping shank, the drilling tool comprising the drill shank, transition section and clamping shank forming a single integral piece, the transition section being heat-treated such that it has higher bending and torsional elasticity compared with at least one of the clamping shank and the drill shank, the drill shank forming a front twist-drill section and an adjoining tap section, the transition section adjoining the tap section with the clamping shank, a countersinking section being arranged between the transition section and the clamping shank.
3. A drilling tool according to claim 2 wherein the tap section consists of a front lead taper adjoining the front twist-drill section and a thread part which adjoins the front lead taper and has teeth with a complete thread profile in cross section, the front lead taper having teeth with cross sections which are reduced in height relative to the teeth of the complete thread profile, a rear lead taper having teeth which are reduced in height relative to the complete thread profile of the thread part.
4. A drilling tool according to claim 2 wherein the tap section has a rear lead taper at its end facing the countersinking section.
5. A drilling tool according to claim 2 wherein the countersinking section has at least one cutting edge.
6. A drilling tool according to claim 2 wherein the countersinking section has two diametrically opposite cutting edges which are arranged obliquely relative to a longitudinal axis of the drill such that a countersinking angle (α) within the range of 60° to 120° is formed.
7. A drilling tool according to claim 3 wherein the drilling tool has a heat-affected region with a main heat zone which is arranged in the transition section at least at about 30% of the length of the transition section starting from the rear lead taper and ending at the countersinking section.
8. A drilling tool according to claim 7 wherein the heat-affected region runs towards the tap section and ends within the rear lead taper.
9. A drilling toot according to claim 7 wherein the heat-affected region runs towards and ends before the countersinking section.
10. A drilling tool according to claim 2 formed of a high-speed steel, the high-speed steel including materials having a material number 1.3343 according to DIN EN 10027 Part 1, or S 6-5-2.
11. A drilling tool according to claim 2 wherein the clamping shank includes a hexagonal cross section and further includes one or more retaining notches in corners of the hexagonal cross section, an encircling groove, or channel-shaped circumferential recesses.
12. A method according to claim 1 wherein the heat treatment is carried out inductively with a high-frequency system within a temperature range of 600°C. to 900°C.
13. A method according to claim 12 wherein the heat treatment is carried out with a reaction time of 0.5 to 2 s.