Stony SDS-PLUS 3D Spiral Bits STY-8160 The Stony STY-8160 SDS-PLUS 3D SPIRAL BITS 8x160. Has particularly high drilling speed through optimized tip geometry with an aggressive cutting-edge profile and large carbide tip angle. Patented (WITH PRINCIPLE) cutting-edge design and strengthened carbide with double centering point guarantee extremely high durability Particularly comfortable and vibration-reduced drilling owing to the innovative Twinmax3-D spiral design which provides optimal removal of drill dust. Rounded cutting edges provide extreme robustness and a low probability of breakage even during reinforcement impacts. Stony SDS-PLUS 3D Spiral Bits Features: 3D Cutting Edge. Hammer Drilling. HST Hardened. Twin Max Flute. Low Vibration. Size / 8x160