Short answer
DENUE lists 277 CNC machining plants with 11 or more staff in Aguascalientes, Guanajuato, Querétaro and San Luis Potosí. 32 have 51 or more staff, and 3 of those match an IMMEX program on exact name and postal code. Querétaro has the most, with 85. Each plant still needs its own checks.
Key facts
- Activity codes (SCIAN)
- 332710
- Plants, 11+ staff
- 277
- Data
- INEGI DENUE bulk files, 25 Sep 2026; IMMEX directory, August 2026 edition
About CNC machining
Machine shops cut parts from bar, casting or forging on turning and milling centres. Most are small: the size bands below show how few reach 51 staff.
The numbers by state
| State | Plants, 11+ staff | With 51+ staff | With an IMMEX match |
|---|---|---|---|
| Querétaro | 85 | 9 | 2 |
| Guanajuato | 75 | 14 | 2 |
| San Luis Potosí | 70 | 7 | 1 |
| Aguascalientes | 47 | 2 | 0 |
| Four states | 277 | 32 | 5 |
| Staff band | Plants |
|---|---|
| 11 to 30 | 215 |
| 31 to 50 | 30 |
| 51 to 100 | 18 |
| 101 to 250 | 10 |
| 251 or more | 4 |
What to ask a CNC machining supplier
Registries show that a plant exists and exports. These questions cover what they cannot.
- Machine types and travel: turning, 3-axis, 4-axis, 5-axis.
- Tolerances held and the inspection equipment behind them, such as a CMM.
- Materials handled, and where the raw material is bought.
- Batch and cell capacity, and how first articles are approved.
- Whether the shop is a stand-alone business or captive to one customer.
Checks before you approach a plant
- Confirm the plant in DENUEName, address, activity code and staff band.
- Check its IMMEX programStatus and type, matched on legal name and postal code.
- Search the SAT 69-B listBy RFC where you have it, otherwise by exact name.
The verification guide explains each step and where it stops.
Frequently asked questions
How many CNC machining plants are in the Bajío?
INEGI’s DENUE lists 277 CNC machining plants with 11 or more staff across Aguascalientes, Guanajuato, Querétaro and San Luis Potosí. 32 of them have 51 or more staff. Testigo counted these from INEGI’s bulk files on 25 September 2026.
Which Bajío state has the most CNC machining plants?
Among the four states Testigo counted, Querétaro has the most CNC machining plants in DENUE, with 85 of 277, followed by Guanajuato (75). Plants elsewhere in Mexico are outside Testigo’s pilot, and counts are establishments in INEGI’s directory as of 25 September 2026.
Do CNC machining plants in the Bajío export under IMMEX?
Some do. 5 of the 277 plants match an IMMEX program on exact name and postal code, and 3 of the 32 with 51 or more staff. A plant with no match may still export through a shelter company’s program, so ask which entity holds it.