Type: Adapter H-BU Advice: Adapter for Hilti machines DD 160 and DD 250 with combi thread: diadrill drill bits with a 1 1/4 inch female thread (0663 230 ...) can be screwed onto the visible male thread; diadrill drill bits with a 1/2 inch male thread (0663 120 ...) can be screwed into the female thread.