Guhring has developed a new series of RT150GG drills specifically for highly abrasive cast iron - its 6000 series. The new design incorporates Guhring’s DK255 F grade of wear-resistant ultra-fine grain carbide. This 8 per cent cobalt grade of carbide can dramatically extend tool life over conventional grades of carbide in applications where tool wear is a primary factor in tool failure. Additionally the 6000 series RT150GG drill has a new point geometry that incorporates a web thinned, four facet point grind unique to this style tool. The facet point provides increased strength behind the cutting edge while the new GN-IC web thinning process makes the tool free cutting in cast materials. The RT150GG produces hole sizes that are in many cases within 0.001 to 0.0005 inch of the nominal specified drill diameter. The straight fluted drill geometry provides a superior hole finish that can exceed a reamed hole quality thus eliminating multiple tool operations. But unlike a gun drill, the RT150GG drill will operate at 2 to 3 times the penetration rate of a traditional carbide drill. Guhring offers three standard length coolant-fed designs: Series 6068 – 4xD Series 6069 – 7xD Series 6070 – 10xD