Short answer
DENUE lists 34 wire forms and springs plants with 11 or more staff in Aguascalientes, Guanajuato, Querétaro and San Luis Potosí. 17 have 51 or more staff, and 8 of those match an IMMEX program on exact name and postal code. Guanajuato has the most, with 12. Each plant still needs its own checks.
Key facts
- Activity codes (SCIAN)
- 332610
- Plants, 11+ staff
- 34
- Data
- INEGI DENUE bulk files, 25 Sep 2026; IMMEX directory, August 2026 edition
About wire forms and springs
These plants form wire and make springs and wire products, from small shops to large auto suppliers.
The numbers by state
| State | Plants, 11+ staff | With 51+ staff | With an IMMEX match |
|---|---|---|---|
| Guanajuato | 12 | 5 | 2 |
| Querétaro | 12 | 8 | 4 |
| San Luis Potosí | 6 | 2 | 1 |
| Aguascalientes | 4 | 2 | 1 |
| Four states | 34 | 17 | 8 |
| Staff band | Plants |
|---|---|
| 11 to 30 | 12 |
| 31 to 50 | 5 |
| 51 to 100 | 2 |
| 101 to 250 | 12 |
| 251 or more | 3 |
What to ask a wire form and spring supplier
Registries show that a plant exists and exports. These questions cover what they cannot.
- Wire diameters and forming machines available.
- Spring testing: load, rate and fatigue where needed.
- Heat treatment and finishing in house or outsourced.
- Material certificates and where the wire is bought.
- Minimum order and lead time.
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 wire forms and springs plants are in the Bajío?
INEGI’s DENUE lists 34 wire forms and springs plants with 11 or more staff across Aguascalientes, Guanajuato, Querétaro and San Luis Potosí. 17 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 wire forms and springs plants?
Among the four states Testigo counted, Guanajuato has the most wire forms and springs plants in DENUE, with 12 of 34, followed by Querétaro (12). Plants elsewhere in Mexico are outside Testigo’s pilot, and counts are establishments in INEGI’s directory as of 25 September 2026.
Do wire forms and springs plants in the Bajío export under IMMEX?
Some do. 8 of the 34 plants match an IMMEX program on exact name and postal code, and 8 of the 17 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.