Standard boring bars require a collet to hold it in the machine toolholder. It is important to find a collet that fits both the machine toolholder and boring bar. Often, much time is spent looking for the proper-sized collet before tooling up a machine for production. This increases time and tooling costs, which equates to a less profitable job.
Also, there are problems with finding a collet that fits the boring bar properly, so a standard boring bar may need to be cut off, wasting one end. Another issue to be concerned with when using a boring bar with a collet is the loss of rigidity that contributes to loss of tolerances. This may further increase unnecessary costs and loss of revenue. Once the boring bar is secured into the collet, it is then necessary to secure the collet properly into the machine toolholder. This takes additional time. Finally, the boring bar is securely loaded into the machine.
To simplify securing a boring bar in its toolholder, MRS Machining has developed the Augusta Cutting Tools (ACT) collet-less boring bar. Because it eliminates the need for a collet, the tool increases production efficiency by saving set-up time, run time and tooling costs. It is also more reliable and accurate.
Rather than using a separate collet, the collet is made as part of the boring bar – one solid piece of metal. This means more rigidity and more accurate parts.
An operator simply slips the collet-less boring bar into the machine toolholder, tightens a screw, and the machine is tooled up. ACT collet-less boring bars come in a variety of lengths (3:1, 4:1 and 5:1) and sizes ranging from 0.5-in. to 1.5-in. diameter; coolant-through tools are also available.