Imperium Tool & Instrument, INC. | Butte | 1–19 | ◐ LIKELY ACTIVE |
R5 Holdings, Inc. dba Midwest Welding & Machine | Bozeman | 20–99 | ◐ LIKELY ACTIVE |
| TETimber Edge Machine INC. | Stevensville | 1–19 | ◐ LIKELY ACTIVE |
| WPWood's Powr-Grip Co., Inc. | Laurel | 100–499 | ◐ LIKELY ACTIVE |
| AMApex Manufacturing Services, LTD | Billings | 1–19 | ◇ UNVERIFIED |
| AFAnaconda Foundry Fabrication Co. Inc | Anaconda | 20–99 | ◐ LIKELY ACTIVE |
Door Systems of Montana Great Falls LLC | Great Falls | — | ◐ LIKELY ACTIVE |
| FIFirstharvest, INC. Dba Montana Steel Industries | Belgrade | 20–99 | ◐ LIKELY ACTIVE |
Koester, Paul | Bozeman | — | ▲ REPORTED CLOSED |
Lawrence Hancock Jr | Victor | — | ◐ LIKELY ACTIVE |
Shield Arms LLC | Bigfork | — | ◐ LIKELY ACTIVE |
| DIDecorative Industrial Plating LLC | Helena | 1–19 | ◇ UNVERIFIED |
| IIIronhaus INC | Hamilton | 20–99 | ◇ UNVERIFIED |
| KMKnick Machining | Bozeman | 1–19 | ◇ UNVERIFIED |
| BHBoeing Helena | Helena | — | ◐ LIKELY ACTIVE |
| CSContinental Steel Works, INC. | Butte | — | ◐ LIKELY ACTIVE |
| CSC Sharps Arms CO INC | Big Timber | — | ◐ LIKELY ACTIVE |
| GMGlacier Machining Solutions, INC. | Columbia Falls | 1–19 | ◐ LIKELY ACTIVE |
| MMMontana Machine & Fabrication L.l.c. | Libby | 1–19 | ◐ LIKELY ACTIVE |
| MRMontana Railroad Services, INC | Joliet | — | ◐ LIKELY ACTIVE |
| SSShiloh Sharps | Big Timber | — | ◐ LIKELY ACTIVE |
| ASAmerican Steel | Billings | — | ◐ LIKELY ACTIVE |
| HPH-e Parts International, Mining Solutions INC. | Billings | — | ◐ LIKELY ACTIVE |
Precision Engineering, INC. | Kalispell | — | ◐ LIKELY ACTIVE |
| AAA and S Industries | Poplar | — | ◇ UNVERIFIED |
| AIAdf Industrial Coatings | Great Falls | — | ◇ UNVERIFIED |
| AIAllison Industries INC | Great Falls | — | ◇ UNVERIFIED |
| APArmor Powder Coating | Missoula | — | ◇ UNVERIFIED |
| BLBay LTD | Billings | — | ◇ UNVERIFIED |
| BSBig Sky Racks INC | Bozeman | — | ◇ UNVERIFIED |
| CICoatings INC Riverside | Billings | — | ◇ UNVERIFIED |
| CMCompatible Manufacturing INC | Marion | — | ◇ UNVERIFIED |
| FLFinishing Lab, LLC | Bozeman | — | ◇ UNVERIFIED |
| JKJ K Fabrication & Supply LLC | Butte | — | ◇ UNVERIFIED |
| PCPowder Coating of Montana Belgrade | Belgrade | — | ◇ UNVERIFIED |
| PMPrecious Metals Plating Hud | Bonner | — | ◇ UNVERIFIED |
| SASpectrum Aquatics | Missoula | — | ◇ UNVERIFIED |
Atomic Industries LLC | Billings | 20–99 | ◐ LIKELY ACTIVE |
| BBelgrade | Belgrade | 1–19 | ◐ LIKELY ACTIVE |
| B1Branch 16 - Billings | Billings | 1–19 | ◐ LIKELY ACTIVE |
| B1Branch 19 - Missoula | Missoula | 1–19 | ◐ LIKELY ACTIVE |
| HAH a Burrow Pattern Works, INC. | Joliet | — | ◐ LIKELY ACTIVE |
| HPH-E Parts International - MSUSA | Billings | 20–99 | ◐ LIKELY ACTIVE |
| OAOlympus Arms, INC | Helena | — | ◐ LIKELY ACTIVE |
| TPThompson Precision INC | Kalispell | — | ◐ LIKELY ACTIVE |
| BSBig Sky Precision INC. | Manhattan | — | ◇ UNVERIFIED |
| ELEarlywood, LLC | Red Lodge | 1–19 | ◇ UNVERIFIED |
| GTGlacier Tool & Die INC. | Stevensville | 1–19 | ◇ UNVERIFIED |
| HSHawe Steel Design | Butte | 1–19 | ◇ UNVERIFIED |
| JIJim-n-i, INC. | Lewistown | — | ◇ UNVERIFIED |