Threaded drill bit is also called threaded shank drill bits, adaptor drill bits or snake drills, which are special purpose rotary cutting tools that have threads on the opposite end. Thread cutting bit screw into a threaded adapter on a handheld drill to enable drilling in tight areas where standard threader bits that install into a chuck can't fit. Those threader drill bits
are usually used for angle and offset drilling. The threaded connection also ensures the bits will not fall off the drill.