Star SU Cutting Tools

Star SU carries a full line of deep hole drilling solutions for a wide range of applications.

Gundrill Models


  • Single Flute – Designed to drill holes from solid material, produce bottom hole configurations and minimize burr at intersections. It can achieve precision holes in one pass, thus eliminating the need for secondary passes, and is a tool for consistent hole-to-hole reproduction. The design of the single-lip, straight deep “V” flutes and high coolant pressure allows for fast, consistent penetration without the need for pecking. Because of the point not being on center, the tool requires either a bushing or a pilot hole starting support. Once into the cut, the tool is self-piloting.
  • Solid Carbide Single Flute – These gundrills have a two-piece construction design. The absence of the braze joint at the head/body transition eliminates the possibility of coolant obstructions while adding significant strength to the tool. Solid carbide gundrills are available from diameter ranges of .039″ [1.00mm] to .200 [5.08mm] and greater with lengths up to 11.25” [286mm]. When a tool enters the material, as well as while it’s drilling, it’s exposed to torque forces, or wind-up, which has a detrimental effect on the carbide, resulting in premature wear. The solid carbide gundrill strength; however, counters the wind-up forces.
  • Two-Flute Two-Hole – Often referred to as the “milled style,” the two-flute two-hole gundrill is engineered with a solid steel body, milled flutes and coolant holes produced internally to allow for optimum coolant flow to the tip. The most common materials drilled are cast irons and cast aluminium applications where materials are free of chip control issues. Two-flute two-hole gundrills are available in diameters from .250″ – 1.0″ with lengths to 48″. This also has a limited flute channel and can only be applied on applications where the chips are smaller in size. Diameters are available from .2500″ – 1.000″. Lengths are available up to 48″.
  • Double Jet – Designed to combat a lack of lubrication, its unique placement of the coolant holes supplies adequate amounts of coolant to the cutting edge. The product line diameter range is .200″ [5.08 mm] through 1.500″ [38.1mm]. The overall lengths can be made to any specific length and lengths over 72″ [1828mm] will have an additional weld joint in the body of the tool. An additional advantage to this style is its ability to break through intersecting holes and/or enter irregular surfaces without premature wear.
  • Double Crimp – Coolant holes in the gundrill body are formed by a crimping action, which minimizes the coolant turbulence at the head/body transition. With the flutes being equally swaged 180 degrees apart, it allow for much greater rigidity. The Double Crimp can obtain feed rates twice that of its single flute partner and can be used for high penetration in softer materials. Diameters are available from .1875″ – .5625″ and lengths are available up to 72″.
  • Bi-Tip – Similar to the Two-Flute Two-Hole “milled style” with a solid steel body, the Bi-Tip has an auger-like helix ground in the body, which allows for better chip evacuation in lower coolant pressure conditions. This enhanced design also allows for higher feed rates and coolant volumes than Star SU’s traditional design. This tool is designed for the machining cast/ductile and CGI materials. The Bi-Tip deep hole drill is available in diameters ranging from .315″ – 1.0″ with maximum flute lengths up to 28″.