Abstract: A sensing apparatus having a body member with a portion engageable with a work object having a medium to be sensed; and a system for registering at predetermined criterion, relative to the body member, during engagement of the portion of the body member with the work object, as an index of the medium. A method for manufacturing a resultant work piece having at least one projection thereon, the method including the steps of cutting a first work material to form the projection on a portion of the first work material, mounting the projection on a second work material and removing the remainder of the first work material from the projection to form the resultant work piece.