A new, modular system for changing small, indexable-insert reamers in a machine spindle quickly and to a high degree of repeatability has been introduced by Horn Cutting Tools. Called DR Small, the tooling comprises four sizes covering diameters from 13.1 mm down to 7.6 mm and is a cost-effective alternative to using solid carbide reamers.

The patented system is believed to be the only quick-change method of attaching a small reamer head to a shank without the need for locking screws. The high-precision interface features keys and slots for rapid, secure attachment, repeatability of position being within 5 μm.

The tools are designed to raise productivity and cut costs by eliminating clocking in the interchangeable head each time it is exchanged, thereby drastically reducing idle times. Such quick-change tooling has the added advantage that a manufacturer does not have to buy extra reamers to maintain production while worn tools are sent away to be reground, saving the associated costs.

The flexibility in terms of shank systems and cutting edges means that a vast array of applications is catered for. Steel and carbide shanks are available in different versions for machining through holes or blind holes, the main difference being in the type of internal coolant supply. The indexable reamer inserts are held in place in the head by a central clamping screw.

The tools will be of particular interest to manufacturers of components in high volumes for the automotive industry, for example. They will also meet the requirements of those producing high value parts where process security is paramount and the variability in surface finish, form and tolerance introduced by boring heads is unacceptable.