PENTAC® cutters (marketed and sold in Japan under SUPERI-AC®) cutters are known for their positive blade seating and the easy axial movement of blades during truing which eliminates blade micro movements and allows more precise building vs. rectangular stick blades and conventional cutters. Those are important factors for cutting with carbide blades in order to avoid chipping of the cutting edges and to assure the equal distribution of the chip load to all blades. PENTAC Plus cutter heads compared to the regular Pentac system show additional advantages.
The Plus stands for a number of improvements especially for three and four face blade geometry. The higher cutter slot angle of 12° assures a positive cutting edge hook angle and at the same time gives a back blades surface that opens the chip chamber to the following blade in order to enhance chip flow and prevent chip packing. The chip flow in face milling is often not sufficient in front of the outside blades, because the side rake angle closes the chip chamber in the direction of the centrifugal force. The PENTAC Plus system uses larger blade spacing in front of outside blades and equally smaller spacing in front of inside blades. This increases the chip chamber an additional amount in order to avoid chip packing and allowing for most aggressive cutting cycles and highest possible tool lives. The improvements in chip flow reduce the cutter head and blade operating temperature, which in turn improves the tool life up to 10%.
Gleason has the solution to prevent chip packing in all high efficient dry cutting processes. Additional spacing where needed, back hook to open up the chip chamber, and additional back face grinding (fourth face) will eliminate the need for fewer blades in PENTAC Plus cutter heads in order to avoid chip packing. The front face grinding offers the freedom of higher effective top rake angles and positive cutting edge hook angles. The new clamp blocks use 2 to 4 spring loaded steel balls which enable in a partially depressed stage a very precise axial blade movement during cutter building and truing. The new features have been developed to account for the significantly higher productivity of Multi-Face, F-Point design carbide blades.
PENTAC Plus cutters are available for face hobbing as well as face milling for the sizes 3.5 inch up to 21 inch cutter diameter. The blade blanks required are identical to the blades for regular Pentac cutters. Recommended are zero raked block blades and three or multi face grinding.
