Abstract:
A flat spring steel element has a handle portion, an offset shank portion, and a blade portion defining a symmetrically ground chisel edge. The edge is oriented at 45. degree. to the handle axis and each end of the chisel edge is ground to define two scoring tips. One of these tips has a 15. degree. forward rake angle when the tool handle is held perpendicular the surface to be scored, and the other tip has a similar rake angle when the tool handle is held at a slightly inclined position relative to such surface.