44 44 S CHLA G BO HRE N P E R CUSSION DRIL L I N G D R EH E N D B OHR E N R OTARY DRILLIN G Special concrete & stone drill bits are used for drilling in concrete and masonry. It is important to use drill bits from certified manufacturing to ensure correct installation of com- ponents. Drilling tolerances may be exceeded if the drill used is not from a monitored production facility. Drills that are too far out of round, or with excessive tolerances in the carbide cutting edge can lead to drill holes that do not give a plug sufficient hold. In extreme cases installed elements will come loose and cause significant damage. DRILLING PROCEDURE QUALITY FEATURES In terms of concrete drill bits, we even recommend using prod- ucts produced as per the regulations of the Masonry Drill Bit Testing Association (PGM), an independent institute. You can identify these bits by the quality mark or the symbol embossed onto the drill bit. Speeds Regardless of the diameter, impact drilling should be carried out at speeds between 2500 – 3000 rpm. TECHNICAL DETAILS CONCRETE AND MASONRY DRILL BITS Material suitability Impact drills are designed for processing masonry, stone and also concrete, depending on the type. The soldered-in car- bide plate means that concrete drill bits can withstand heavy loads. However, special products are required to cut through reinforcements. Cleaning the hole Before fitting a plug, you should always remove material res- idues from the drill hole to guarantee the best possible hold for the plug. HELLER QUALITY FOR LONG-TERM OUTSTANDING RESULTS TIPS AND TRICKS Heller exclusively uses the best steel and tungsten carbide plates for its concrete and masonry drill bits. At the same time, accurate processing is paramount, for instance as a re- sult of the precise alignment and soldering of carbide plates or a strict concentricity tolerance. Finally, aspects, such as ergonomics and occupational safety are paramount. In this process, we aim at meeting professional users’ demands. After all, all Heller products contribute to faster and more economical working for professionals. Impact drilling Concrete, sand lime brick, natural stone, masonry, brick Impact-free fotating drilling Aerated concrete, hard burnt tiles, fibre cement panels, light sand lime brick, wall tiles