Posted February 26, 2023

Micro drills to machine all ISO materials

Sandvik Coromant has introduced two new micro drills: CoroDrill 462 with -XM geometry and CoroDrill 862 with -GM geometry. The tools are ideal for precision drilling in industries that deal with small parts such as medical, aerospace, automotive, general engineering, electronics and watchmaking, among others.

This range of micro drills is available to support machining in all ISO materials: P, M, K, S, O and H. The new geometries offer a wide range of cutting diameters and lengths.Sandvik Coromont micro drills-022623

Sandvik Coromant tooling specialists compared the performance of a major micro drill competitor’s tool against the CoroDrill 862 with -GM geometry. Each tool was run in a DMG Mori Seiki Milltap 700 machine, for the purpose of drilling blind holes in an ISO M 316L stainless steel workpiece. The same tool setting was used in each case, a cutting diameter of 2.5 mm (Dc) with a speed (vc) of 40 m/min and a feed rate of 0.04 (fn) mm/z.

The results were clear: the competitor’s tool produced 630 holes before reaching tool life. Meanwhile, the CoroDrill 862 produced 1,260 holes, a more than 100% increase in tool life over the competitor’s drill.

Sandvik Coromant’s engineers recommend that customers seeking to drill micro-sized holes in notoriously difficult-to-machine materials, such as titanium, aluminium, glass and ceramics, should consider polycrystalline diamond (PCD) coating for extended tool life in these demanding applications. Based on successful tests of PCD drills on micro parts made from platinum, Sandvik Coromant has found that PCD is up to 100 times more wear-resistant than solid carbide, is also more accurate and can produce tighter tolerances than solid carbide tools.

Coolant is another important consideration. As with macroscale applications, it’s also critical to have quality coolant delivery to effectively evacuate chips when performing deep-hole drilling with micro tools. The immediate benefits of coolant include extended tool life and reduced risk of chip jamming.

These features have clear advantages for manufacturers’ overall operational expenditure (OPEX), and can also help manufacturers strike a balance between quality versus productivity when micro drilling tough materials like ISO M. In doing so, to paraphrase Steve Jobs, they can ensure the small things are unforgettable for all the right reasons.