Great for dados and shallow grooves in laminated or wood materials. The downshear puts downward force on the top edge of the material so it helps reduce chipping or poor finish on the top edge of your material. If you are experiencing flaking or problems on the top edge of your wood or laminated materials and need the cleanest edge the downshear tool will help. The downshear may pack debris in the bottom of the slot more than an upshear tool. So shallower slots, profile cuts, or taking multiple passes in deep slots is recommended to help with the chip evacuation. Downshear tools are also excellent for using on vacuum tables because they do not pull the material up but help push it down on the vacuum table. Also look at Herringbone or compression routers that have both up and downshear in one tool.