If a part has machining operations — drilling, grooves, milling, cut-outs — it goes to the CNC machine as a machining program. Every program has a code: a short string of digits. The code is printed as a barcode on the part label and at the same time serves as the program name in the machine files. The operator scans the barcode and the machine opens exactly the program this part needs.
Why it matters. The code can be read at a glance: it tells you which part it is, which order it belongs to, which program in sequence it is and which side is being machined. That helps when a file goes missing, the wrong program opens, or you have to find the part manually in the machine program list.
How the code is built
The code is a solid string of digits — no dots, hyphens or spaces. Read it position by position, left to right:
| Position | Meaning | Example |
|---|---|---|
| 1–3 | Part number within the order, padded with zeros to three digits. It is the same number printed on the label | part 7 → 007part 42 → 042part 128 → 128 |
| 4–7 | Last four digits of the order number | order 123456 → 3456 |
| 8 | Program number for this part | 1, 2, 3 … |
| 9 | Machined side: 1 — face, 9 — back | 1 or 9 |
Example
Part no. 7 of order 123456, first program, face side:
007 + 3456 + 1 + 1 = 00734561
The back side of the same part is already the second program:
007 + 3456 + 2 + 9 = 00734629
Why a part can carry two barcodes
One program means one side of the part in one position on the machine table. Hence the rule:
- operations on the face side only — one program, one barcode (the upper one);
- operations on both sides — two programs and two barcodes: the upper one belongs to the face side, the lower one to the back;
- no machining operations at all — no programs, and no barcode is printed on the label.
Under each barcode the code is repeated in plain digits: if the label is damaged and the scanner cannot read it, the code can be typed in by hand.
What the program number means
The program number is not just a counter. It defines the side of the part and its rotation on the machine table:
| Number | Side | Part rotation | Code ends with |
|---|---|---|---|
| 1 | face | no rotation | 11 |
| 2 | back | no rotation | 29 |
| 3 | face | 90° | 31 |
| 4 | back | 90° | 49 |
| 5 | face | 180° | 51 |
| 6 | back | 180° | 69 |
| 7 | face | 270° | 71 |
| 8 | back | 270° | 89 |
| 0 | face | no rotation | 01 |
| 1, moved to the back side | back | no rotation | 19 |
| mirrored | face | vertical mirroring | 10 |
Rotation is needed when the operations do not fit the working area or the tool has to approach the part from another direction. Only programs that actually contain operations are exported — empty ones are skipped and never reach the label. That is why an ordinary part machined on both sides carries codes ending in 11 and 29, numbers 3–8 show up far less often, and the last three rows of the table are the special cases explained below.
Special cases
- Post-processing of compact laminate after cutting on the milling machine is split off into a separate program numbered
0. Its code ends with01. - Operations with vertical mirroring go into their own program, whose code ends with
10. - Double-sided machine, part with no face-side operations. The first program is then moved to the back side and its code is recalculated — it ends with
19.
Files and folders in the export
Machine files are laid out in folders whose names contain the full order number, with the individual part programs inside.
Important. The code itself contains only the last four digits of the order number. This means that orders differing only in the leading digits — for example 123456 and 223456 — produce identical part codes. As long as the programs stay in their own order folders, this is safe. But if files from different orders are dropped into one shared folder, programs with the same name overwrite each other and the machine receives the wrong machining. Do not mix exports of different orders in one directory and do not rename the folders by hand.