| LOLatrobe Operations | Latrobe | PA | 100–499 | ◐ LIKELY ACTIVE |
| LFLaX Fabricating LTD - Spring Grove MN | Spring Grove | MN | 20–99 | ◐ LIKELY ACTIVE |
| LFLaX Fabricating LTD - Westby WI | Westby | WI | 20–99 | ◐ LIKELY ACTIVE |
Legacy Building Solutions LLC | South Haven | MN | 100–499 | ◐ LIKELY ACTIVE |
| LELevy Environmental Services Company dba Brandenburg Mill Service | Brandenburg | KY | 20–99 | ◐ LIKELY ACTIVE |
| LELevy Environmental Services Company dba Butler Mill Service | Butler | IN | 20–99 | ◐ LIKELY ACTIVE |
| LELevy Environmental Services Company dba Charleston Mill Service | Huger | SC | 20–99 | ◐ LIKELY ACTIVE |
| LELevy Environmental Services Company dba Columbia City Mill Services | Columbia City | IN | 20–99 | ◐ LIKELY ACTIVE |
| LELevy Environmental Services Company dba Fulton Mill Service | Delta | OH | 20–99 | ◐ LIKELY ACTIVE |
| LELevy Environmental Services Company dba Levy Big River | Osceola | AR | 100–499 | ◐ LIKELY ACTIVE |
| LELevy Environmental Services Company dba Levy Gallatin Mill Service | Ghent | KY | 20–99 | ◐ LIKELY ACTIVE |
| LELevy Environmental Services Company dba Levy NYS Mill Service | Blytheville | AR | 20–99 | ◐ LIKELY ACTIVE |
| LELevy Environmental Services Company dba Levy Texas Mill Services | Sinton | TX | 20–99 | ◐ LIKELY ACTIVE |
| LELevy Environmental Services Company dba SeaTac Steel Mill and Recycling Services | Seattle | WA | 1–19 | ◐ LIKELY ACTIVE |
| LSLivingSpace Sunrooms, LLC | Maumee | OH | 20–99 | ◐ LIKELY ACTIVE |
| LTLockhart, TX | Lockhart | TX | 20–99 | ◐ LIKELY ACTIVE |
| LOLockport Operations | Loc | NY | 20–99 | ◐ LIKELY ACTIVE |
| LLLSM - Latrobe | Latrobe | PA | 500+ | ◐ LIKELY ACTIVE |
| LSLSM - Sandy Creek | Franklin | PA | 20–99 | ◐ LIKELY ACTIVE |
| LMLucas Metal Works | Ochelata | OK | 20–99 | ◐ LIKELY ACTIVE |
| MCMacArthur Company - Energy Panel Structures IA | Graettinger | IA | 100–499 | ◐ LIKELY ACTIVE |
| MCMacArthur Company - Energy Panel Structures MO | Perryville | MO | 20–99 | ◐ LIKELY ACTIVE |
| MFMain Facility | Shreveport | LA | 100–499 | ◐ LIKELY ACTIVE |
| MOMain Office - 009 | Memphis | TN | 20–99 | ◐ LIKELY ACTIVE |
| MMMarion Manufacturing, Inc. | Marion | KS | 20–99 | ◐ LIKELY ACTIVE |
| MMMarshall, MI | Marshall | MI | 20–99 | ◐ LIKELY ACTIVE |
| MBMaster Builders & Erectors CORP | Folcroft | PA | — | ◐ LIKELY ACTIVE |
| MSMaverick Steel Group, LLC | Hendersonville | NC | — | ◐ LIKELY ACTIVE |
| MEMaya Erectos, LLC | Houston | TX | 20–99 | ◐ LIKELY ACTIVE |
| MHMBCI Houston Hardy | Houston | TX | 100–499 | ◐ LIKELY ACTIVE |
| MMdac | Mount Airy | NC | 1–19 | ◐ LIKELY ACTIVE |
| MFMedford Fabrication | Medford | OR | 1–19 | ◐ LIKELY ACTIVE |
| MJMedtronic JAXs | Jacksonville | FL | 500+ | ◐ LIKELY ACTIVE |
| MSMedtronic Santa Clara | Santa Clara | CA | 20–99 | ◐ LIKELY ACTIVE |
| MSMeeco Sullivan | Warwick | NY | 20–99 | ◐ LIKELY ACTIVE |
| MSMeeco Sullivan | Mcalester | OK | 20–99 | ◐ LIKELY ACTIVE |
| MMMemphis Mill Service Company | Memphis | TN | 20–99 | ◐ LIKELY ACTIVE |
| MMerkel | Merkel | TX | 20–99 | ◐ LIKELY ACTIVE |
| MMetalac | Latrobe | PA | 1–19 | ◐ LIKELY ACTIVE |
| MBMetal Building Construction and Supply, LLC | Lawton | OK | — | ◐ LIKELY ACTIVE |
| MSMetal Sales - Fontana | Fontana | CA | 20–99 | ◐ LIKELY ACTIVE |
| MSMetal Sales Manufacturing Corp - Nashville | Antioch | TN | 20–99 | ◐ LIKELY ACTIVE |
| MSMetal Sales Manufacturing LLC | Mocksville | NC | 1–19 | ◐ LIKELY ACTIVE |
| MSMetal Sales Manufacturing LLC | Temple | TX | 20–99 | ◐ LIKELY ACTIVE |
| MSMetal Sales MC - Woodland | Woodland | CA | 20–99 | ◐ LIKELY ACTIVE |
| MSMetal Sales Mfg. | Anchorage | AK | 1–19 | ◐ LIKELY ACTIVE |
| MSMetal Sales Mfg. Corp. - Detroit LAkes | Metal Sales/1435 Egret Ave/Detroit Lakes | MN | 20–99 | ◐ LIKELY ACTIVE |
| MSMetalsa Sequence Center SA | San Antonio | TX | 20–99 | ◐ LIKELY ACTIVE |
| MSMetalsa Sequence Center SH | Sterling Heights | MI | 20–99 | ◐ LIKELY ACTIVE |
| MSMetal Solutions - Ballinger | Ballinger | TX | 100–499 | ◐ LIKELY ACTIVE |