System for securing an anchor in a mineral substrate

A system for fastening an anchor in a borehole in concrete, mortar or masonry, comprising:

• an anchor having a core section and a thread section, the core section having a core diameter dK and the thread section having an outer diameter dG;
• and
• a grooving tool for grooving an internal thread in the borehole, the grooving tool comprising the following:
• a base body having a leading and a trailing end, a force application device being provided, via which a torque for screwing the grooving tool into the borehole and for grooving the thread is transmitted to the base body, the base body having an outer surface on which a grooving thread is formed, which is suitable for grooving the internal thread into the wall of the borehole;
• the following applying to the ratio of a length heff of the thread section of the anchor and a nominal diameter db of the borehole:
• heff/db≥12.0,
• wherein the anchor is produced with a manufacturing tolerance of less than 0.2·(db)0.3 mm in relation to the outer diameter dG of its thread, the grooving tool is produced with a manufacturing tolerance of less than 0.2·(db)0.3 mm in relation to the maximum outer diameter dF of its grooving thread, wherein db is the numerical value of the nominal diameter of the borehole in millimeters, and wherein the following applies:
• 0.0≤(dF−dG)/dK≤0.15.

A system for fastening an anchor in a borehole in concrete, mortar or masonry, comprising:

• an anchor having a core section and a thread section, the core section having a core diameter dK and the thread section having an outer diameter dG;
• and
• a grooving tool for grooving an internal thread in the borehole, the grooving tool comprising the following:
• a base body having a leading and a trailing end, a force application device being provided, via which a torque for screwing the grooving tool into the borehole and for grooving the thread is transmitted to the base body, the base body having an outer surface on which a grooving thread is formed, which is suitable for grooving the internal thread into the wall of the borehole, the following applying to the ratio of a length heff of the thread section of the anchor and a nominal diameter db of the borehole:
• heff/db≥12.0,
• wherein the grooving tool has a drive element at its leading end, which is suitable to interact with a force application device of the anchor or a part of the same, which is to be screwed into the borehole treated with the grooving tool.

A method for fastening an anchor having a core section and a thread section in a borehole in a mineral substrate, comprising the following steps:

• drilling a borehole;
• grooving an internal thread in the borehole by screwing a grooving tool into the borehole;
• and
• inserting the anchor into the borehole;
• the grooving tool comprising the following:
• a base body having a leading and a trailing end, a force application device being provided via which a torque for screwing the grooving tool into the borehole and for grooving the thread is transferred to the base body, the base body having an outer surface on which a grooving thread is formed, which is suitable for grooving the inner thread into a wall of the borehole, wherein the anchor is inserted into the borehole with an effective anchoring depth heff, wherein the following applies to the ratio of the effective anchoring depth heff and a nominal diameter db of the borehole:
• heff/db≥12.0,
• wherein the anchor is formed in at least two parts and comprises the following:
• a spiral coil which can be screwed into the internal thread in the borehole grooved with the aid of the grooving tool;
• and
• a screw or threaded rod having an external thread which can be screwed into the spiral coil;
• and
• wherein said insertion of the anchor into the borehole comprises the following:
• screwing the spiral coil into the internal thread in the borehole that has been grooved with the aid of the grooving tool;
• and
• thereafter screwing the screw or threaded rod into the spiral coil, and wherein
• the grooving tool at its leading end has a drive element suitable for interacting with a force application device of the anchor or of a part of the same, and with the aid of which the anchor or the part of the same is screwed into the borehole treated with the grooving tool.