Tooling specialist Mapal Ltd, Rugby (www.mapal.com), has developed a tool concept that makes the machining of bores with medium to large diameters and substantial lengths more productive and significantly more reliable.

The company’s spring-loaded guide pads offer smooth running and high cutting speeds, machine stability and process reliability, which translate to significant time savings.

Traditionally, engineers have found that boring operations on deep bores presented them with two fundamental challenges.

The length of the tools required in conjunction with a large tool head led to vibration; furthermore, variations in the material structure of the raw part required different stock removal rates.

This resulted in single- or twin-blade tools with a low weight being used, but to achieve process reliability, these have to be operated at low cutting speeds.

Mapal has designed tool heads that accommodate up to eight indexable inserts.

The stability and reliability of the machining operation are ensured through a combination of conventional fixed guide pads and spring-loaded guide pads (patent pending); the latter are positioned in such a way that the spring force makes the fixed guide pads lie perfectly against the material of the bore and support the tool, thereby guaranteeing smooth machining even with fluctuating stock removal rates or wear of the inserts.

The result is excellent bore quality, even when using high cutting speeds.