"O" Flutes for mechanical plastics

When cutting soft plastics it is good to utilize single edge "O" flute geometry which tends to curl a chip during the machining process. This tooling when properly applied within a narrow range of chipload (Typically .004" to .012") . The consequence of the improperly curled chips is visible knife marks that adversely affect the finish.
The only caution with single edge tooling is to avoid using diameters over 3/8" because of balance issues associated with the tooling. If larger diameters are needed, the double edge alleviates the balance problem while providing a much improved bottom finish for slotting applications.
The double edge tools additionally provide longer cutting edges for deeper cuts of two to four times the cutting edge diameter at fast feed rates.