Material, machine time, setup costs, inspection – where the levers are.

If you send inquiries to a turned-parts supplier without understanding the costing logic, you routinely give away money – either because you accept quotes that are too cheap (and fall apart later) or too expensive (because you don't know where to negotiate). This article is the inside view from a CNC contract turning shop with 77 years of practice.

A typical CNC turned-part unit price is made up of five items: material costs, machine hours, setup costs, inspection/documentation and overhead/margin. The proportions vary widely by part and quantity – but the pattern stays the same.

Material costs: typically 20–40 percent of the unit price for series turned parts. With expensive special materials (titanium, high-conductivity copper alloys) up to 60 percent. Important: material costs include cut-off waste – on Swiss-type parts, around 10–25 percent ends up as chips, part of which is recouped as scrap revenue but still costs money net. If your drawing demands overly generous material allowances, you pay for it.

Machine hours: between 25 and 50 percent of the unit price for good Swiss-type series. What matters here is the machining time per piece – length of machining, number of tools, spindle speeds, feed rates. More complex geometries double or triple the machining time without giving the customer any more function. This is where the design has the biggest lever.

Setup costs: a fixed block allocated across the series. A setup time of 4–6 hours is realistic on a Swiss-type automatic (loading tools, verifying the program, running first articles, releasing). With a lot size of 100 pieces: 6 hours ÷ 100 = 3.6 minutes of setup per piece. With a lot size of 10,000 pieces: 6 hours ÷ 10,000 = 2.2 seconds per piece. Hence the enormous unit-price difference between small and large series.

Inspection and documentation: 5–15 percent is typical. At the lower end for simple parts with sample-based inspection. At the upper end for first article inspection to VDA 2 Level 3, documented 100 % inspection of critical dimensions and external third-party inspections. If you demand documented quality, you also pay for it – that is legitimate, but it should be shown transparently.

Overhead/margin: 10–25 percent. This covers administration, sales, plant overhead, machine maintenance and of course entrepreneurial profit. At a mid-sized CNC turned-parts supplier in Germany, this item is transparently calculable – if a supplier bids well below the usual level, either margin is missing (= risky) or quality (= expensive down the line).

Practical levers for buyers and design engineers: 1) Review tolerances (see separate article). 2) Question material selection (see separate article). 3) Optimize lot size – sometimes it pays to order quarterly instead of monthly, because setup costs spread better. 4) Bundle several parts with the same supplier – that reduces setup effort and administrative costs. 5) For regular customers, consider consignment stock models – that lowers the buyer's logistics costs and allows the supplier to plan more efficiently.

One-time costs should be cleanly separated from the unit price. CAM programming, the building of fixtures and clamping devices, and the first article effort (first article inspection to VDA 2) occur only once, regardless of the later lot size. Hiding these 300 to 2,000 euros proportionally in the unit price distorts every follow-up costing and penalizes reorders. We therefore state the start-up as a separate one-time item. That keeps the unit price stable for repeat orders, and you can see transparently which effort belongs to preparation and which to the actual production.

Material prices fluctuate considerably. Stainless steel such as 1.4404 tracks nickel and molybdenum quotations, non-ferrous metals such as brass CuZn39Pb3 follow the copper prices on the metal exchanges; swings of 10 to 30 percent within a year are not uncommon. In framework agreements over longer terms, we handle this fairly via a material surcharge or index linking: the machining share stays fixed, only the material share floats against a disclosed quotation. That protects both sides from speculation and makes price adjustments traceable instead of arbitrary.

Buyers regularly overlook certain ancillary costs. Packaging and preservation (such as oiling or VCI protection against corrosion for 1.4404) cost a few cents to euros per part depending on the specification. Add small-quantity surcharges when a lot falls below the economical setup threshold, plus logistics and, where applicable, special tooling. Especially with very small series below 50 pieces, tooling and setup costs per part weigh heavily and can exceed the pure machining price. We name these items openly in the quote so you can compare total costs and not just the nominal unit price.

We check feasibility, suggest optimizations and get back to you within 48 hours with a first assessment.