router was used on a light router table, 1/4" ash boards were beveled at 7.5 degrees and after about 30 minutes of operation the dovetail router head broke the shank 1/2". Examining the Brittle fracture surface shows the start of a crack in the notch, probably created by residual cutter marks on the shank along the radius of the cutter I should have known, always use the Whiteside club now ordered.