Materials in precision mechanics — metals and alloys

When a drawing lands on the table, there's usually a material name in the bill-of-materials field—but behind that name lies a whole range of properties that determine how you should clamp the piece, which cutting tool you need, and how fast the machine can run. Knowing the materials is just as important as being able to operate the machine.

§Stainless steel — strength and corrosion resistance

Stainless steel is used where the part must withstand moisture, chemicals or hygiene requirements, for example in medical technology and food equipment. The common austenitic stainless steel (such as AISI 304 and 316) is tough and corrosion-resistant, but also more demanding and heat-sensitive to machine than ordinary steel — it work-hardens easily, which means that incorrect cutting speed or dull tools quickly give a hard, glazed surface that is difficult to proceed with.

§Brass — the grateful material

Brass is a copper-zinc alloy, and in fine mechanics especially free-cutting brass (with a small addition of lead or bismuth) is favoured because it gives short, manageable chips and a beautiful surface without extra polishing. It is used for everything from watches and instruments to fittings and valves. The disadvantage is that brass is softer than steel and is not suitable for heavily loaded or wear-exposed parts.

§Aluminum – light and quick to process

Aluminum alloys weigh about one-third of steel and can be processed at high speeds, making the material popular for components, fittings, and parts where weight matters. On the other hand, aluminum is softer and less durable, and it easily forms a natural oxide layer that protects the surface – but which also must be taken into account if the part is later to be anodized or soldered.

§Spring steel and tool steel — hard and tough at the same time

Springs locks and wear surfaces require steel that can be hardened and tempered to a specific hardness without becoming brittle. Spring steel (often a carbon or chromium-vanadium alloy) is shaped and machined while soft then hardened in a heat treatment process where temperature and cooling time control the final hardness and toughness. Tool steel is used for cutters dies and wear-resistant parts where surface hardness matters more than weight.

§Titanium and special materials in medical and aviation

In medical device technology, and lighter aircraft components, you sometimes encounter titanium, which combines low weight with high strength and good biocompatibility, but which is far more difficult to machine than aluminium — it conducts heat poorly, which concentrates heat in the cut and requires lower speed, ample cooling and sharp, often coated tools.

Regardless of which speciality you choose, you build on the same professional foundation: understanding of engine, hydraulics, electrics and mechanics, combined with a systematic and safe working method. It is this combination that makes a plant mechanic a valued professional, whether the machine is in a field or on a building site.