As a CNC contract manufacturer, we see daily requests that unnecessarily cost time and money – not because of the parts themselves, but because of avoidable ordering mistakes. Here are the 5 most common pitfalls and how to avoid them.
Mistake 1: Missing or Unclear Tolerances
If no tolerances are specified on the drawing, we manufacture to ISO 2768-m (medium). This can mean a 50mm dimension may vary by ±0.3mm. If that's too much for your part, specify critical dimensions explicitly.
Mistake 2: Wrong File Format
We ideally need a 3D STEP model (.stp/.step) plus a 2D drawing with tolerances and surface specifications.
Mistake 3: Unrealistic Lead Times
Standard lead time for CNC parts: 2-3 weeks. Express is possible (1 week) but costs extra.
Mistake 4: Material Not Specified
"Made of stainless steel" is not enough. Specify the material number (e.g., 1.4301 instead of "V2A").
Mistake 5: Unclear Quantities
The quantity determines the price per part significantly. Specify your annual demand – we can often offer better conditions through framework agreements.
Questions about ordering? Contact us – we're happy to help with optimal specification of your CNC parts.
Frequently Asked Questions
What file format do I need for CNC parts?
Ideally a 3D STEP model (.stp/.step) plus a 2D drawing (PDF) with tolerances and surface specifications. STEP is the universal exchange format accepted by all CNC manufacturers.
How long does CNC manufacturing take?
Standard lead time is 2-3 weeks. Express manufacturing within one week is available at additional cost. See our cost guide for single parts vs. series.
At what quantity do CNC parts get cheaper?
From 5 pieces, unit costs drop significantly. The sweet spot for small series is 5-500 pieces. Details in our material selection guide.