Jeweler's 16pc Precision Mini Drill Bit Set 1.0mm to 2.0mm HSS Micro-sized twist drill bits for fine-detail drilling with jewelry, electronics 16 bits starting at 1.00mm and up to 2.0mm by 0.05mm increments (1.2mm shown for size reference High speed steel for durability and strength For hand or power drilling; for hand drilling, use pin vise Bit lengths 1-1/4" to 1-7/8"; also in micro-size 0.25mm to 1.0mm & small 2.05mm to 3.0mm