Materials in CNC Contract Manufacturing

In your enquiry, please state the material if possible with the material number or standard designation.

• S235 and S355: structural steels, easy to weld and machine. S355 can bear higher loads and is preferred for load-bearing parts and machine frames.
• C45: unalloyed quenched and tempered steel, often used for shafts and pins.
• 42CrMo4 and 34CrNiMo6: alloyed quenched and tempered steels for highly loaded shafts and large cross-sections. Thanks to its nickel content, 34CrNiMo6 stays very tough even in large cross-sections.
• 16MnCr5 and 18CrNiMo7-6: case-hardening steels for gears and transmission parts, with a hard surface layer and a tough core.
• 1.2379 and 1.2312: tool steels for cutting tools, moulds and fixtures.

You can read more about machining these steels on the pages CNC milling and Turning and grinding.

• 1.4301 (V2A): the most widely used austenitic stainless steel for general applications.
• 1.4404 and 1.4571 (often V4A): contain molybdenum and are more resistant than 1.4301 to media containing chlorides, such as salt water or cleaning agents.
• Duplex 1.4462: significantly higher strength than 1.4404, particularly resistant to pitting and stress corrosion cracking, for example in seawater and chemical engineering.
• 1.4305: regarded as particularly easy to machine. However, the added sulphur reduces corrosion resistance and weldability.

Austenitic stainless steels tend to work-harden during machining, and duplex requires stable clamping and adapted cutting data. We take this into account when selecting tools and cutting values.

Grey cast iron (EN-GJL) dampens vibrations well and is typical for housings and machine beds. Ductile cast iron (EN-GJS) is tougher and can bear higher loads, for example for hubs and bearing housings. Cast steel is tougher than cast iron and dampens vibrations less than grey cast iron.

MWA machines all three, including as free-issue raw parts. On request, we obtain raw castings through our partner network and machine them to completion. What matters for large castings is explained on the page Large-part machining.

Aluminium weighs about a third as much as steel and can be machined economically at high cutting speeds.

• EN AW-6082: good strength, machinability and weldability, a solid standard choice for milled parts in mechanical engineering.
• EN AW-7075: one of the strongest aluminium alloys, but only of limited weldability.
• EN AW-5083: non-hardenable and particularly resistant to seawater.

Yes. For plain bearings and bushings, tin bronzes such as CuSn8 and CuSn12-C and the aluminium bronze CuAl10Ni5Fe4 are common; we machine bronze as bar stock and as raw castings. For brass turned parts, CW614N is widely used, and low-lead grades are available for lead content requirements.

Titanium is considered demanding to machine because of its low thermal conductivity. Grade 2 is commercially pure titanium with very good corrosion resistance, and Ti6Al4V (Grade 5) is the most widely used titanium alloy, with high strength. Send us the drawing and requirements for a feasibility check.

Both are possible. If we procure the material, it is included in the quote. Free-issue material is worthwhile if you want to use special materials, raw parts such as castings or forgings, or existing stock. Through our commodity trading, you can also buy material only.

Yes, on request we supply material certificates according to EN 10204 (2.2 or 3.1). For traceability down to the batch, request a certificate 3.1 and, if required, state your specifications for marking the parts. The difference is explained in our guide Material certificate according to EN 10204.

• Material number or standard designation, for example 1.7225 or 42CrMo4,
• desired delivery condition, for example quenched and tempered or soft annealed,
• heat treatment and hardness, for example in HRC or HV,
• desired material certificate,
• whether we procure the material or you supply it.

If the grade has not yet been decided, describe the intended use to us, and we will suggest suitable materials with their advantages and disadvantages. The fastest way is via our enquiry form with file upload.