For small diameter boring and internal turning operations, Tungaloy Corporation has developed its DoMiniBore range of toolholders and inserts. Capable of machining bore diameters as small as 12 mm, the new DoMiniBore is said to be a cost-effective solution for the machining of stainless steels and cast irons.
With double sided inserts, the new DoMiniBore offers twice the number of corners of conventional positive type inserts from competitors. This significantly reduces tooling costs, while the insert design enables one insert type to fit shank diameters from 10 to 20 mm to further reduce costs and tooling inventory.
The DoMiniBore incorporates a unique new edge shape and large inclination that reduces the cutting forces considerably and prevents chattering to deliver performance levels beyond that of positive type inserts.
The inserts are available in left or right hand designations with G-Class accuracy to guarantee impeccable surface finishes and quality levels. The large edge inclination minimises cutting forces and chatter, while the unique chipbreaker design is said to offer excellent chip control over a wide range of material types.
The wide chip pocket enhances chip control and also minimises the potential for re-cutting the chips, which can be a cause for poor surface finishes. This chip pocket works in synergy with the peripheral insert shape that delivers the clamping rigidity required for high performance boring and internal turning.
The steel or carbide toolholders are available with shank diameters from 10 to 20 mm for minimum bore diameter machining from 12 to 22 mm and upwards. The toolholders have an innovative new wedge shape pocket design that ensures the optimal fit for the insert.
Working with a dovetail system, the insert and toolholder work in combination to deliver "remarkable" rigidity and accuracy for high performance boring operations. This highly rigid clamping structure further improves insert tool life and productivity, say the company.
The toolholder shanks offer a through-coolant facility, with the oil hole located directly above the cutting edge to maximise swarf removal and cooling of the work envelope. To ensure the chips are evacuated as efficiently as possible, the toolholders have a large chip pocket that is comparable with positive inserts, while the limited rake angle generates low cutting forces.
For internal facing and boring, Tungaloy has developed its SWLXR toolholder shank that is available in right or left-hand options and for minimum bore diameters of 12, 14, 18 and 22 mm, with toolholder shank diameters of 10, 12, 16 and 20 mm, respectively.
Capable of achieving machining depths of 125, 150, 180 and 200 mm, the steel shank series has an optimal design to maximise machining performance. While the carbide shank offers identical machining parameters to the steel shank holders, the improved rigidity enables the carbide series to machine at depths of 150 to 250 mm. This shank overhang length exceeds anything available from competitors whilst offering enhanced rigidity and machining performance.
For internal profiling operations, the steel and carbide shanks offer minimum bore diameters of 13, 16, 20 and 24 mm, with a maximum machining depth from 125 to 200 for the steel shank and 150 to 250 for the carbide bars.
Author: Andrew Allcock