An apparatus for measuring the width dimension of a helical surface of an endmill. The apparatus includes a workholder capable of supporting an endmill in such a position as to optically magnify the surface of the endmill to be measured. The workholder further includes an index arbor capable of rotating...http://www.google.sh/patents/US5105545?utm_source=gb-gplus-sharePatent US5105545 - Apparatus for measuring a width dimension of a helical surface
