What Does CNC Contract Manufacturing Cost? The Cost Factors

• Material: material price, machinability and the shape of the raw part,
• Batch size: how many parts share the one-off preparations?
• Tolerances and surfaces: how precise and how fine must the part be?
• Geometry: how many setups, pockets, holes and special shapes does it have?
• Setup and programming: clamping devices, tools, CNC program and first part,
• Inspection and documentation: measurement report, first article inspection report, material certificate,
• Additional services and deadline: heat treatment, coating, packaging, transport and urgent requirements.

The factors work together. A simple part made of a material that is easy to machine can be more expensive in small quantities than a complex part in a large series.

The material affects the price twice: through the material price and through the machining time. Aluminium can usually be machined quickly. Tough materials such as stainless steel or titanium require slower cuts and wear the tools more.

The shape of the raw part also counts: a semi-finished product close to the finished dimension saves machining, while a large block produces a lot of chips. If a material certificate according to EN 10204 is required, the material must be procured with a certificate. More in the guides Materials in CNC contract manufacturing and Material certificate according to EN 10204.

Before the first chip is cut, there is work that arises only once per order: creating the CNC program, setting up clamping devices and tools, and manufacturing and inspecting the first part. With a single part, that one part bears the entire effort; in a series, it is spread over many parts.

For repeat parts, the effort drops because the program and clamping concept already exist. Feel free to state several quantities in your enquiry, so that the quotation shows how the unit price changes with quantity. More on the path from sample to series on the page From prototype to series.

The tighter the tolerance and the finer the surface, the greater the effort: slower finishing passes, additional operations such as grinding, more measuring time and a higher risk of scrap. That is why the rule is: as precise as necessary, not as precise as possible.

Where the function does not require particular precision, a general tolerance according to ISO 2768 is usually sufficient. Tight tolerances belong on fits, bearing seats and sealing surfaces. More in the guide General tolerances according to ISO 2768.

It gets expensive when a part has to be reclamped often, when there are deep pockets with small inner radii, thin walls or undercuts, or when special tools are needed. Every additional setup costs setup time and can affect accuracy.

For multi-sided and inclined contours, 5-axis machining can save setups. Which process suits which part is explained in the guide Turning, milling or 5-axis milling?.

• Inspection documents such as measurement report, first article inspection report and material certificate,
• heat treatment, for example stress relieving or hardening,
• coating or surface treatment,
• marking, packaging and transport,
• short delivery dates that require production to be rescheduled.

Please state these points already in the enquiry. They are then included in the quotation, and there are no subsequent additional charges.

• State tight tolerances and fine surfaces only where the function requires them,
• choose inner radii in pockets so that standard cutters fit,
• use standard threads instead of special threads,
• choose a readily available material that is easy to machine, if the application allows it,
• base raw dimensions on standard semi-finished products,
• combine requirements into larger lots or call them off as a framework order,
• send complete documents so that no queries delay the process.

During the feasibility check, we point out such items to you before costs arise.

With a quotation based on your drawing. Send us the drawing or 3D model (for example STEP), material, quantity and desired date. Information on surfaces, heat treatment, coating, inspection documents and the type of delivery is also helpful.

At MWA, quotation and feasibility check are free of charge and non-binding. MWA manufactures small to medium-sized parts up to Ø 2,500 mm, 6,000 mm in length, 3,000 mm in height and 25 t, from prototype to series. Tips for a fair quotation comparison can be found in the guide Choosing a CNC contract manufacturer. You can send your enquiry via the page Contact.