The present invention is a positioning work stop for use with a with a machining apparatus for performing a machining operation on a work piece, the positioning work stop comprising a retractable element having an extended position for contacting a work piece to ensure that the work piece is in its proper position for machining and a retracted position that provides a gap between the positioning work stop and the work piece, a biasing element that exerts a rearward biasing force of the retractable element, and a stop pin, wherein during the machining operation, when the machining apparatus contacts the stop pin the rearward biasing force automatically moves the retractable element into its retracted position creating a gap between the positioning work stop and the work piece.