| LSLee Spring Company Plainville CT | Plainville | 1–19 | ◐ LIKELY ACTIVE |
| LSLennox Steel LLC | Trumbull | — | ◐ LIKELY ACTIVE |
| LMLinde Manchester | Manchester | 20–99 | ◐ LIKELY ACTIVE |
| LNLinde North Haven | North Haven | 20–99 | ◐ LIKELY ACTIVE |
| LJL & J Metal Works L.l.c. | Danbury | — | ◐ LIKELY ACTIVE |
| MOMan of Steel Welding Services LLC | Seymour | — | ◐ LIKELY ACTIVE |
| MMMcGuire Manufacturing Co., Inc | Chesire | 1–19 | ◐ LIKELY ACTIVE |
| MPMcWane Plant & Industrial - Wethersfield | Wethersfield | 1–19 | ◐ LIKELY ACTIVE |
| MIMetal Improvement Company, LLC | East Windsor | — | ◐ LIKELY ACTIVE |
| MIMetal Improvement LLC DBA Curtiss Wright Surface Tech | East Windsor | 20–99 | ◐ LIKELY ACTIVE |
| MUMetals USA - Gregor Technologies | Torrington | 20–99 | ◐ LIKELY ACTIVE |
| MHMfs Holdings Incorporated | Stafford Springs | — | ◐ LIKELY ACTIVE |
| MMMillers Manufacturing LLC | North Franklin | — | ◐ LIKELY ACTIVE |
Monroe Engineering Group LLC | North Branford | 20–99 | ◐ LIKELY ACTIVE |
| MEMorin East | Bristol | 20–99 | ◐ LIKELY ACTIVE |
| NPNc Precision LLC | Putnam | — | ◐ LIKELY ACTIVE |
N.c.t., INC. | Colchester, | — | ◐ LIKELY ACTIVE |
| NBNew Britain Hand Tools, Stanley Black & Decker | New Britain | 100–499 | ◐ LIKELY ACTIVE |
| NSNewcomb Spring CORP. | Southington | — | ◐ LIKELY ACTIVE |
| NENew England Plasma Development Corporation | Putnam | 20–99 | ◐ LIKELY ACTIVE |
| NGNext Generation Construction, LLC | Stratford | — | ◐ LIKELY ACTIVE |
| NTNiantic Tool, INC. | Niantic | — | ◐ LIKELY ACTIVE |
| OTOetiker Tool Corporation | Wallingford | 20–99 | ◐ LIKELY ACTIVE |
| OTOtoole Tek LLC | Rocky Hill | — | ◐ LIKELY ACTIVE |
| PIPdq, INC | Rocky Hill | — | ◐ LIKELY ACTIVE |
| PTPetit Tool Company | Thomaston | — | ◐ LIKELY ACTIVE |
| PPettipaug | Westbrook | 100–499 | ◐ LIKELY ACTIVE |
| PMPinto Manufacturing, LLC | Glastonbury | — | ◐ LIKELY ACTIVE |
| PGPlug Group | Westbrook | 20–99 | ◐ LIKELY ACTIVE |
Polamer Precision Inc - Blg 2 | Newington | 1–19 | ◐ LIKELY ACTIVE |
| PDPomaski, Don | Collinsville | — | ◐ LIKELY ACTIVE |
| PPPorobond Products, LLC | Hamden | — | ◐ LIKELY ACTIVE |
| PMPp Middletown Holdings, LLC | Middletown | — | ◐ LIKELY ACTIVE |
| PLProiron, L.l.c. | West Haven | — | ◐ LIKELY ACTIVE |
| PLPrtc LLC | South Windsor | — | ◐ LIKELY ACTIVE |
| QLQuinnovations LLC | Glastonbury | — | ◐ LIKELY ACTIVE |
| RTReady Tool LLC | Wethersfield | — | ◐ LIKELY ACTIVE |
REM Chemicals Inc. RU1 CT | Southington | 1–19 | ◐ LIKELY ACTIVE |
| RGRestrictor Group | Westbrook | 100–499 | ◐ LIKELY ACTIVE |
| RBRoller Bearing Company of America, INC. | Fairfield | — | ◐ LIKELY ACTIVE |
| RBRoller Bearing Company of America, INC. | Oxford | — | ◐ LIKELY ACTIVE |
| RBRoller Bearing CO of America, INC | Middlebury | — | ◐ LIKELY ACTIVE |
| RARps Associates of New England | Somers | 20–99 | ◐ LIKELY ACTIVE |
| SCSaar CORP | Farmington | — | ▲ REPORTED CLOSED |
| SASchaeffler Aerospace USA - Winsted | Winsted | 20–99 | ◐ LIKELY ACTIVE |
| SPSheldon Precision, LLC | Prospect | — | ◐ LIKELY ACTIVE |
Shepard Steel Co., Inc. - Miscellaneous Metals | Newington | 20–99 | ◐ LIKELY ACTIVE |
Shepard Steel Co., Inc. - Structural Steel | Hartford | 20–99 | ◐ LIKELY ACTIVE |
| SDSilgan Dispensing Systems Covit America Corporation, DBA Silgan Aluminum Solutions (Seemar) | Watertown | 20–99 | ◐ LIKELY ACTIVE |
| SDSilgan Dispensing Systems Covit America Corporation, DBA Silgan Aluminum Solutions (Waterbury) | Waterbury | 20–99 | ◐ LIKELY ACTIVE |