Drill flank measurement and flank/flute intersection determination

Twist drill is a cutting tool of large-batch and diversified varieties. Geometric measurement is indispensable to drill design, manufacture, and regrinding. To meet the demand of advance in manufacturing technology, a three-dimensional (3-D) drill measurement instrument was developed. Method of drill flank and flute measurement by using this device is presented in this work. Cutting angles evaluation is essential to cutting performance appraisal. But, there is no suitable instrument yet to inspect them directly. If the flank/flute intersection is determined, cutting angles calculation would be a routine work of numerical computation. Considering the peculiarity of the drill point configuration, a straightforward method for flank/flute intersection is derived. Procedure of cutting angles calculation is also detailed. The procedure is illustrated by an example of flank and flute inspection, flank/flute intersection, and cutting angles calculation for a standard twist drill. The measurement precision is appraised by using a tool-room microscopy. The maximum error is in the third decimal place. It verifies the validity of the developed 3-D drill meter and the proposed measurement methods.