Since the introduction of numerical control (CNC) technology, digital display technology has been used extensively on CNC machine tools and coordinate measuring machines. In addition, digital display micrometers, digital display calipers and other digital display gauges have also been widely used. However, the application of digital display technology on precision boring tools has been slow, and its constraints are mainly the coolant used in the boring process and the high-speed rotation of the boring head.

In the past, great care had to be taken when boring on a machining center to avoid splashing coolant into the electronics of the head's digital display unit. Today, new boring tools with an internal cooling design are a better solution to this problem. Since the coolant can be directed to the cutting area through a channel inside the tool, the coolant is completely isolated from the boring head display. In addition, the new CNC boring tool is sealed on the outside to prevent the coolant from coming into contact with the electronic components in the digital display.

In high-speed boring operations, the high speed rotation of the boring head, centrifugal force and the unbalance of the head itself can cause large vibrations that can damage the sensitive digital display unit. The new boring head uses a built-in balancing mechanism to reduce or eliminate harmful vibration during high speed boring. The precision boring head with digital readout has been designed for high-speed boring at speeds up to 16,000 r/min.

The new heads have a digital display that directly indicates the displacement of the boring slide, rather than having to determine the displacement by the rotation of the tool setting screw. Since the boring bar is mounted directly on the boring slide, the digital display of the head can truly reflect the displacement of the boring tool without the influence of screw clearance errors. This feature of the digital boring head allows for faster and more precise adjustment of the boring diameter and allows for error compensation for machining deviations or tool wear.

Most boring tools require a cut-and-measure operation to determine their set size, where a small portion of the bore being machined is first test bored and then the bore diameter is measured. Often, this means removing the boring tool from the machine and mounting it on a tool setter to fine-tune the size of the boring tool to obtain the correct bore size. This pre-adjustment operation is necessary because it is quite difficult to read and pre-adjust the vernier dials on a common boring head directly on the machine tool, however, this operation can result in oversize bores or damage to the workpiece.

Since it is difficult to predict the tip deviation of a boring tool when it is mounted on the machine, a test-cut-measure operation is required to precondition the tool. With the new easy-to-read digital boring tool, it is possible to fine tune the tool bore diameter directly on the machine spindle. Even if the boring tool must be removed from the machine for bore size adjustment due to the feed limitations of the machine spindle, the new digital boring tool is a faster and more accurate process.