Version:
Spiral fluted, with 6 guide chamfers and internal cooling channels. New generation of high performance deep hole drills in the HPC range. With 135° point angle and special h7 cutting edge tolerance for optimum generation of a deep hole. High roundness and alignment accuracy of the deep hole.
Note:
Flute length L
C = L
2 + 1.5 × D
C.
For process reliability when using the 16×D deep hole drill, an initial centre drilling with No.
121068 –
121121 or 4×D pilot drilling operation with pilot drill No.
122606 is necessary. For deep holes greater than 20×D, a pilot hole to the maximum drilling depth with pilot drill No.
122606 is absolutely essential.
The generation of a pilot hole improves process reliability. See also pages 140/141.