Note :Flute length LC = L2 + 1.5 × DC. For process reliability when using the 16×D deep-hole drill, an initial centre drilling with No. 121068 – 121121 or at least 4×D pilot drilling operation with pilot drill No. 123885 is necessary. For deep holes greater than 20×D, a pilot hole to the maximum drilling depth with pilot drill No. 123885 is absolutely essential. The generation of a pilot hole improves process reliability. The specified L/D ratio gives the minimum achievable depth of hole with the respective deep-hole drill.

Version :Excellent chip evacuation due to the unequal helical pitch of the flutes, guide rings and additional guide chamfers for very high precision when drilling. Maximum process reliability due to exactly matching tools within the overall system. Drilling up to the maximum depth without a pilot drill. Significantly increased tool stability due to the substantially strengthened core. Increased metal removal rates and outstanding tool lives lead to an economical high-end drilling process.