AB Grąžtai makes industrial-quality HSS and cobalt HSS (HSSCo) drills for metal – standard and special – and special end mills for aluminium, PVC and soft plastics. Standard drills are made to DIN 338, DIN 339, DIN 340, DIN 341, DIN 345 and DIN 1869 (see Drill standards). Special-purpose drills are made to customers’ drawings.
HSS or HSSCo?
- HSS (high-speed steel) drills are used for carbon, alloy and structural steels and cast iron.
- HSSCo (cobalt high-speed steel) contains cobalt, which makes the drill harder, more wear-resistant and more heat-resistant. An HSSCo drill makes 1.5–2 times more holes than an HSS drill. HSSCo drills are used for hard-to-machine materials, titanium and titanium alloys, and stainless steels.
Point types
- Standard point – for general drilling where there are no special requirements for hole accuracy.
- Split point – for professional use. The split point stops the drill from wandering away from the marked centre (“walking”), cuts into the metal faster and with less feed force, and in most cases no centre punch is needed.