Star SU, with its years of experience in gundrilling, developed a Star-patented Double Jet Gundrill. The most critical interface, in which the carbide is subjected to the most traumas, is during entry and exit of the part. This is caused by the lack of lubricity to the cutting edges. The double jet was designed to combat this type of condition with its unique placement of the coolant holes supplying adequate amounts of coolant to the cutting edge.
Star SU’s double jet product line diameter range is .200" [5.08 mm] through 1.500" [38.1mm]. The overall lengths can be made to any speciﬁc length. Lengths over 72" [1828mm] will have an additional weld joint in the body of the tool. An additional advantage to this style gundrill is its ability to break through intersecting holes and/or enter irregular surfaces without premature wear. The unique coolant hole location also assists in kick off burrs that can occur during break through. As with all gundrills straightness, concentricity, size and ﬁnishes are obtained.