1/2° Taper 4 Flute Corner Radius Rib Tool - Series 261 Series 261 1/2° Taper 4 Flute Corner Radius Rib Tool Features: Designed to improve production in high speed machining of deep, tight grooves in plastic injection molds Eliminates time-consuming EDM burnig operations resulting in a bench free rib Reduce cycle times with faster speeds and feeds Degree Taper is per side AlTiN coating allows for dry machining and extends the life of the tool Standard with Corner Radius.