Tools for boring and milling with very long projection lengths tend to vibrate due to insufficient dynamic rigidity. When designing new tool-holding systems, Mapal product developers took into account all factors arising from the interaction of the machine tool, the cutting tool, the type of clamping and the part. The result is a system for vibration damping that is matched to the stiffness of all common machine types, and can be used for cutting different types of materials with a variety of tools.

Mapal’s self-contained system of auxiliary mass and several steel spring packages, counteracts and minimises tool-body deflection. Vibration in the system can be up to 1,000 times lower compared with tools that are not supported by the absorber system. Despite long tool projection lengths, quiet and stable running is achieved, while cutter performance is said to be significantly improved, making it possible to work at higher cutting speeds and increase material removal rate.

In addition, improved surface finishes are achieved. When milling case hardened steel (16MnCr5) with a 250 mm long combination of milling cutter arbor and cutter with ISO indexable inserts (50 mm diameter) featuring five edges, the Rz value was halved from 7.8 to 3.9 micron (3 mm depth of cut) compared with the same tool system minus vibration damping.

Milling cutter arbors with vibration damping in the shank are available from Mapal with internal coolant supply for clamping diameters of 16, 22 and 27 mm, with a length of 200 or 300 mm. At present, these tool-holding adaptors are available for SK40, SK50, HSK-A63 and HSK-A100 connections.