| NMNick's Metal Fabricating & Sons, INC. | Chicago | — | ◇ UNVERIFIED |
| NANorth American Electroless Nickel | Elk Grove Village | — | ◇ UNVERIFIED |
| OMO'Brien Metal Inc. | Chicago | — | ◇ UNVERIFIED |
| OKO & K American CORP. | Chicago | — | ◇ UNVERIFIED |
| OIOrion Industries, LTD. | Chicago | — | ◇ UNVERIFIED |
| OIOrion Industries, LTD. | Chicago | — | ◇ UNVERIFIED |
| OMOsorio Metals Supply, Inc. | Chicago | — | ◇ UNVERIFIED |
| PPPark Productions INC | Melrose Park | — | ◇ UNVERIFIED |
| PPPaulsen Pipe, LLC | South Holland | — | ◇ UNVERIFIED |
| PSPerfection Spring & Stamping CORP | Mount Prospect | — | ◇ UNVERIFIED |
| PTPerfect Temperature Control, INC. Dba Fab-rite Sheet Metal | Des Plaines | — | ◇ UNVERIFIED |
| PFPhoenix Fabricators, LLC | Chicago | — | ◇ UNVERIFIED |
| PGPiw Group, LLC | Park Ridge | — | ◇ UNVERIFIED |
| PAP.m. Armor, INC. | Mount Prospect | — | ◇ UNVERIFIED |
| PHPolar Hardware Mfg. CO. INC. | Chicago | — | ◇ UNVERIFIED |
| PLPrecise Lapping and Grinding Corp | Melrose Park | — | ◇ UNVERIFIED |
| PMPreferred Machine & Tool | Bedford Park | — | ◇ UNVERIFIED |
| PSPromet Steel INC. | Chicago | — | ◇ UNVERIFIED |
| RFRd Franklin Ave LLC | Franklin Park | — | ◇ UNVERIFIED |
| RPReyco Precision Welding INC. | Elk Grove Village | — | ◇ UNVERIFIED |
| RERezny Enterprises, Inc. | Franklin Park | — | ◇ UNVERIFIED |
| RMRhyno Manufacturing Inc | Wheeling | — | ◇ UNVERIFIED |
| RMRockbound Manufacturing INC. | Franklin Park | — | ◇ UNVERIFIED |
| RMRockbound Manufacturing INC. | Elk Grove Village | — | ◇ UNVERIFIED |
| RSRomero Steel Company, INC. | Melrose Park | — | ◇ UNVERIFIED |
| RMRoscoe Metal Finishing | Chicago | — | ◇ UNVERIFIED |
| RERra Enterprises, LLC | Chicago | — | ◇ UNVERIFIED |
| SMSate-lite Manufacturing CO | Niles | — | ◇ UNVERIFIED |
| SESchram Enterprises, INC. | Melrose Park | — | ◇ UNVERIFIED |
| SSSinger Safety Company | Chicago | — | ◇ UNVERIFIED |
| SMSinter Metals INC | Richton Park | — | ◇ UNVERIFIED |
| SASlidematic Acquisition, LLC Dba Slidematic Products | Chicago | — | ◇ UNVERIFIED |
| STSobot Tool and Mfg. Co., INC. | Northbrook | — | ◇ UNVERIFIED |
| SSSouth Shore Iron Works | Chicago | — | ◇ UNVERIFIED |
| SMSpeed Machine Inc. | Bridgeview | — | ◇ UNVERIFIED |
| SAStairs and Rails INC. | Melrose Park | — | ◇ UNVERIFIED |
| SPStandard Precision Grinding CO. | Lansing | — | ◇ UNVERIFIED |
 Sterling Spring, L.l.c | Chicago | — | ◇ UNVERIFIED |
| SPStone Perforating | Chicago | — | ◇ UNVERIFIED |
| SPSundstrom Pressed Steel CO | Chicago | — | ◇ UNVERIFIED |
| SMSupreme Manufacturing Company, Dba C & L Supreme Manufacturing Company | Des Plaines | — | ◇ UNVERIFIED |
| SPSwiss Precision Machining INC. | Wheeling | — | ◇ UNVERIFIED |
| TCTal-mar Custom Metal Fabricators, INC. | Crestwood | — | ◇ UNVERIFIED |
| TBTanko Brothers Screw Machine Products Corporation | Chicago Heights | — | ◇ UNVERIFIED |
| TITaycorp Inc | Alsip | — | ◇ UNVERIFIED |
| TMTelco Machine and Mfg., INC. | Chicago | — | ◇ UNVERIFIED |
| TSTemme Spring Clutch & Brake | Chicago | — | ◇ UNVERIFIED |
| TFThe Finishing Touch | Chicago | — | ◇ UNVERIFIED |
| TITower International - Chicago | Chicago | — | ◇ UNVERIFIED |
| TCTru Coat Plating and Finishing Company, INC. | Bellwood | — | ◇ UNVERIFIED |
