Milling Cutters

Milling cutters are rotary cutting tools that are clamped onto a drill or a straight grinding tool and remove material as they rotate. They are used to drill and enlarge holes, smooth edges, remove burrs and shape metal, wood or plastic. They are among the most essential consumables used in a workshop or machine shop.

The carbide grinder is made of hard metal, so it can cut through steel, stainless steel and cast iron without becoming blunt quickly. It rotates at high speeds and removes material where a standard cutter would struggle. At Geosantro, you’ll find individual cutters as well as sets of ten with different head shapes.

The multi-drill has stepped holes, so you can drill a range of diameters – usually from 4 to 20 millimetres – using just one drill bit. It’s ideal for sheet metal, electrical panels, cupboards and thin sheets, as you don’t have to keep changing the drill bit. The hole comes out clean and round, with far fewer burrs.

The coating is a thin, hard layer on the cutter that reduces friction and keeps the temperature low. Titanium is suitable for general use, whilst ALTIN withstands higher temperatures and is ideal for hard metals and faster cutting. In practice, a coated drill bit will drill significantly more holes before it needs replacing.

The rule is simple: the larger the diameter and the harder the material, the lower the speed. Small carbide cutters require high revs to cut cleanly, whilst a multi-hole drill bit on sheet metal works best at a slow speed and with steady pressure. High speeds on a large-diameter bit will cause the cutter to overheat.

On metal, yes, it helps a lot. A little cutting oil on the area you’re working on keeps the cutter cool, produces cleaner chips and easily doubles its service life. With wood and plastics, you shouldn’t use anything, as the material will melt or stick. With stainless steel and aluminium, oil is almost essential.

The first sign is that you have to apply much more pressure for the cut to progress. This is followed by a whistling sound, excessive heat, blackening at the tip and shavings coming out as dust rather than in a spiral. At this point, change it: a clogged cutter will damage both itself and the piece you’re working on.

Most have a round shank and can be fitted to a bench drill, a hand drill or a straight grinder, provided the chuck can accommodate the shank diameter. Carbide grinders perform best on high-speed tools. Before you buy, check that the shank diameter matches the chuck you have.

If you’re just starting out or if your projects are constantly changing, this set’s got you covered because it includes a variety of shapes and diameters at a better price per piece. However, if you know you’ll be working with the same diameter time and time again, it’s better to buy individual cutters and replace them as soon as they become blunt.

From Geosantro, via online order or from our shops in Limassol and Nicosia. You’ll find carbide grinders, multi-hole drills and router bit sets, with free delivery throughout Cyprus on orders over 50 euros. If you’re not sure which diameter or shape is right for you, just ask us before you order.