Shop accuracy begins with a benchmark straightedge as a surface reference. These Canadian-made precision steel straightedges are ground flat over the entire length on both edges, the 12" length to within 0.0010" and the 24" and 36" lengths to within 0.0015". All have been stress relieved to remain true under temperature variation. Useful for checking whether surfaces are flat or straight, they are 1 1/2" high and their width allows them to easily stand on edge unsupported, leaving both hands free for precise measurement or tool adjustment. All have hang holes, allowing storage on a nail or hook.
At just over 1 lb and 1/4" thick, the 12" straightedge is a handy size for checking things such as plane soles or water stones for flatness. It is also a good choice anywhere a larger straightedge would be unwieldy in use or would risk damaging the item being checked.