Corestar International Corporation | Irwin | 20–99 | ● ACTIVE |
Irwin Automation INC | Greensburg | — | ● ACTIVE |
| PDPrecision Defense Services INC | Irwin | 100–499 | ● ACTIVE |
| VIVersa-fab INC. | New Kensington | 20–99 | ● ACTIVE |
Cnc Specialties Manufacturing INC | Apollo | — | ● ACTIVE |
Emb Machining Services INC | Whitney | — | ● ACTIVE |
General Carbide Corporation | Greensburg | 100–499 | ● ACTIVE |
J.b. Anderson & Son, INC | Irwin | — | ● ACTIVE |
Kennametal INC | Latrobe | — | ● ACTIVE |
Kiski Precision Industries, LLC | Leechburg | 20–99 | ● ACTIVE |
Leese & CO INC | Greensburg | — | ● ACTIVE |
Linear Machining Technology LLC | Irwin | — | ● ACTIVE |
Painter Tool Incorporated | Irwin | — | ● ACTIVE |
| QMQuality Machined Products and Manufacturing, INC. | New Kensington | 20–99 | ● ACTIVE |
Accrotool, INC. | New Kensington | — | ● ACTIVE |
Accurate Marking Products, INC. | New Kensington | — | ● ACTIVE |
Acme Machine & Welding Co., LLC | New Kensington | — | ● ACTIVE |
Astley Precision Machine Company, INC. | Irwin | — | ● ACTIVE |
| DSDura-bond Steel CORP | Export | 20–99 | ● ACTIVE |
| FPFalcone Precision Machine, INC. | Latrobe | — | ● ACTIVE |
General Nuclear CORP | Hunker | — | ● ACTIVE |
Gibson Stainless & Specialty, INC. | Greensburg | — | ● ACTIVE |
H R Edgar Machining & Fabricating, INC. | New Kensington | — | ● ACTIVE |
| KBKey Bellevilles INC | Leechburg | 20–99 | ● ACTIVE |
Overly Door CO | Greensburg | — | ● ACTIVE |
| PSPenn State Tool & Die CORP | Mount Pleasant | 20–99 | ● ACTIVE |
| RTRe:build Tps I, LLC | New Kensington | 20–99 | ● ACTIVE |
Steel City Structures LLC | Harrison City | — | ● ACTIVE |
Tri-form INC | Arnold | — | ● ACTIVE |
| MMMoore & Morford INC | Greensburg | 20–99 | ◐ LIKELY ACTIVE |
| PIPbm INC | Irwin | 100–499 | ◐ LIKELY ACTIVE |
| CBCannon Boiler Works | New Kensington | 20–99 | ◐ LIKELY ACTIVE |
| DMDf Mfg Inc/hydro Carbide Tool CO | Latrobe | — | ◐ LIKELY ACTIVE |
| EPExport Plt | Export | — | ◇ UNVERIFIED |
| FPFulmer / Perma Cast a Division of Motive Power, INC | Export | — | ◇ UNVERIFIED |
| KRKeystone Rustproofing INC | Arnold | — | ◇ UNVERIFIED |
| AGAggressive Grinding Svc INC | Latrobe | — | ◐ LIKELY ACTIVE |
| DPDura-Metal Products Corporation | Irwin | 20–99 | ◐ LIKELY ACTIVE |
| FMFarzati Manufacturing Corp. | Greensburg | 20–99 | ◐ LIKELY ACTIVE |
| HIHolan, INC | Irwin | — | ◐ LIKELY ACTIVE |
| HWH W Nicholson Welding & Manufacturing INC | Apollo | — | ◐ LIKELY ACTIVE |
| JFJ. F. Burns Machine Co., INC. | Export | 20–99 | ◐ LIKELY ACTIVE |
| KMKin-tech Mfg INC | Irwin | — | ◐ LIKELY ACTIVE |
| LPLesleh Precision INC | Rostraver Township | — | ◐ LIKELY ACTIVE |
| MFMetal Finishing Industries, INC. | Greensburg | — | ◐ LIKELY ACTIVE |
| OOrrco | Greensburg | 20–99 | ◐ LIKELY ACTIVE |
| PCPlum CORP | Greensburg | — | ◐ LIKELY ACTIVE |
| SMSkovira Machine CO | Scottdale | — | ◐ LIKELY ACTIVE |
| SPStellar Precision Components. LTD. | Jeannette | — | ▲ REPORTED CLOSED |
| TSTooling Specialists, INC. | Latrobe | — | ◐ LIKELY ACTIVE |