Providing tooling solutions since 1991
Petra - DTH & Rotary Hole Making Drills
  • For machining of bore holes for button bits in rock drills in the mining industry, MSTM’s Petra drill series is used. The very stringent requirements of the application and the methods with which MSTM combats them is discussed below.
  • Low bore ovality - In-house R&D developed geometry helps in maintaining tight bore tolerances. Tool parameters such as flute design, chip-breaking geometry, edge design and roundness have been optimized to achieve this.
  • Smooth bore surface finish - MSTM’s in-house HiPIMS coating is customized to withstand the heavy-duty machining of this application. The high hardness property of the coating gives excellent wear resistance leading to smooth bore surface finish.
  • Proper fitting of button bit - Stringent quality control with tight tolerances of Run out of ± 0.002 mm, angle tolerance of ± 10’ is maintained to ensure the button bit fits into the bore perfectly. This cuts down on rework machining time and reduces scrap page.
  • Consistency of bore parameters over tool life - Ultrafine carbide grade helps in retention of cutting edge over long periods of machining, improving productivity and lower tooling costs.