A totally new range of plunge-cut drills and milling cutters that use a flat cutting edge to create a near-flat-bottom profile has been released by Sumitomo Electric Hardmetal Ltd, Princes Risborough (www.sumitomo-hardmetal.co.uk).

In action, both tool types significantly reduce any variation (taper) in the remaining stock material left at the bottom of a blind pocket or chamber (this can adversely influence finishing cuts). As a result, these tools can be used for applications relating to aerospace, mould and die, housings, pumps and valve bodies.

The two SEC cutter types — PDL (plunge drill) and PCT (plunge mill) — are fed in the vertical axis, so the inserts are positioned to provide maximum rigidity, especially when an extended tool overhang is involved. Indeed,
the level of rigidity achieved by the PDL plunge drill is such that it allows radial cuts beyond the radius of the tool to be undertaken.

Meanwhile, the number of insert positions in the PCT plunge mill allows not only the use of high feed rates but also the medium finishing of corner features, the expansion of existing holes and bores and the milling of deep grooves. Both tools can be used on a wide spectrum of materials, including soft steels, stainless steels and hardened steels up to 45HRC. Grey and ductile cast irons, aluminium and copper alloys can also be machined.

PDL holders for 2xD and 3xD depth-to-diameter ratios and PCT holders for 3xD and 5xD are available in diameters of 16, 20, 25, 32 and 40mm — each with a through-coolant capability.