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.