MERCOVIACNC machining for small batches: how to find the right supplier
Ten prototypes are easy. Ten thousand parts are easy. The hard part is everything in between — a first series of 50, 200 or 500 pieces, ordered by a team without a purchasing department. This guide explains why small batches are hard to place with CNC machining suppliers, what an enquiry needs so shops can actually quote it, and how to pick the right shop.
Last updated: October 2026
Why small batches are hard to place
For a machine shop, every new part starts with fixed work before the first chip falls: reading the drawing, writing and proving the CNC program, building or adapting fixtures, setting up the machine and measuring the first article. On a run of 5,000 parts that effort disappears into the unit price. On a run of 50 it dominates it.
That is why many contract manufacturers set a minimum order quantity or quietly deprioritise small enquiries when their machines are busy. It is not a judgement on your project — it is how their capacity planning works. The practical consequence: phoning down a supplier list wastes days on shops that were never going to take your quantity.
What a quotable enquiry contains
Incomplete enquiries are the second reason small orders stall. A shop can only quote what it can price. Send these with every request:
- 3D model. A STEP file is the common exchange format and can be opened by almost every CAM system.
- 2D drawing with tolerances. Critical dimensions, fits and surface finishes. Everything not toleranced explicitly falls under a general tolerance, typically ISO 2768.
- Material. The exact designation, e.g. EN AW-5754 (AlMg3) instead of just “aluminium”.
- Quantity and call-offs. The batch you need now and the volume you expect later. Shops price a first series differently when a follow-up is likely.
- Post-processing. Anodising, coating, heat treatment, deburring, marking — each one changes who can deliver.
- Certificates. If you need a material certificate, say which one, for example an inspection certificate 3.1 according to EN 10204.
- Target date. A realistic delivery date, not “as soon as possible”.
How to choose a CNC machining supplier
- Process and working envelope. Can the shop mill or turn your geometry, and does the part fit its machines? 3-axis, 5-axis and mill-turn centres solve different problems.
- Minimum order quantity. Ask first, not last. A shop whose minimum is 1,000 pieces is the wrong partner for 200, however good it is.
- Material experience. Aluminium, stainless steel and engineering plastics machine very differently. Ask what the shop runs every week.
- Quality evidence. An ISO 9001 certificate says the shop has a quality management system. It does not prove it can hold your tolerance — ask how first articles are measured and documented.
- Communication. On a first series, questions will come up. A shop that answers them quickly is worth more than a slightly lower unit price.
Small batch CNC machining
What counts as a small batch in CNC machining?
There is no fixed definition. In practice, quantities from a few dozen to a few hundred parts are where set-up effort still weighs heavily on the unit price — too many for a prototype service, too few for many production shops.
Why is the unit price so much higher for small batches?
Programming, fixturing, machine set-up and first-article inspection are fixed effort per order. Spread over 50 parts they add much more to each part than spread over 5,000. Grouping orders or agreeing on call-offs for a larger annual quantity can lower the unit price.
Should I use an instant-quote platform or a direct supplier?
Instant-quote platforms are fast for standard geometries and you do not need to know the shop. Working directly with a contract manufacturer pays off when the part needs technical discussion, when you expect follow-up orders, or when you want to know who makes your part.
Which files do CNC suppliers need for a quote?
A 3D model (usually STEP) plus a 2D drawing with tolerances, surface requirements and the material designation. Add quantity, post-processing, required certificates and the target date.