Adapters for BDS core drills. With the appropriate adapters, BDS core drills with Weldon shanks are compatible with all standard machines and tool holder systems on the market. For BDS core drills with Weldon shank – suitable for third-party systems with adaption. Tool holders for BDS core drills with Weldon holder. There are now a total of three systems to choose from, which enable a stable, comfortable and safe connection between the core drill and the magnetic core drilling machine.