Unibit or Move-Bit: A steel-cutting drill bit with stepped-diameter slicing edges to enable easy drilling holes in preset increments in stamped/rolled metallic up to about 1.6mm (one/16 inch) thick. Frequently used to generate custom knock-outs inside a breaker panel or junction box. In case you have fears that a http://emiliomljhf.theobloggers.com/1344689/the-ultimate-guide-to-electrician