New Drills Deepen Productivity Gains

1 September 2021

The productivity of deep hole drilling has now taken a huge step forward with the arrival of a new 4-fluted series of gun drills from Guhring. The new VB 80 4-fluted deep hole drills with a solid carbide head and the solid carbide VB 100 Series is the ideal productivity partners for cast iron drilling.

The straight flute deep hole drills are extremely robust with a geometry that ensures the drill core is more than 50% of the overall diameter, demonstrating maximum rigidity, strength and performance. Guhring has also developed an innovative geometry that consists of two core cutting edges that are supported by four outer flutes that are axially displaced to split the chips, improve centring and precision whilst reducing cutting forces. This means the bottom of the hole will be two-stepped, as the drill has a 141-degree angle on the primary cutting edge, which is followed by a 145-degree cutting angle on the outer cutting edges. The chip clearance is further improved by four cooling channels that allow high-pressure coolant to be directed to each of the four cutting edges – prolonging tool life by preventing swarf re-cutting and creating an efficient chip removal sequence.

The new VB 80 and VB 100 deep hole drills also consist of four round margins with a 90-degree division that further enhances precision, concentricity and surface finishes down to IT6. With the abrasive wear divided through 4-flutes as opposed to two, as in most ranges, the new VB 80 and VB 100 have proven to improve tool life and performance significantly. In fact, the new deep hole drills have reduced cycle times by more than 30% during field tests whilst also extending tool life, hole quality and overall performance far beyond the realms of 2-flute gun drill variants.

At present, the new VB 80 and VB 100 Series is available in diameters from 13.5 to 28mm diameter with flute lengths up to 500mm. Additional diameters and lengths can be specified upon request. The new drills can be reground from 5 to 10 times depending upon the axial wear on the drills. This regrinding facility drastically reduces cutting tool costs for the end-user with the drills being returned in a perfect ‘as-new’ condition. At present, the VB 80 and VB 100 are new product lines and Guhring is working tirelessly to develop an extended range of drill diameter and length options whilst trialling the exciting new drills on a host of additional materials, an exercise that will undoubtedly create huge productivity enhancements for manufacturers.