| KPKearney Pattern Works and Foundry, INC | San Jose | CA | Primary Metal Manufacturing331524 | — | ◇ UNVERIFIED |
| KMKearneys' Metals, Inc., Dba Kmi Dba Kearneys' Dba | Fresno | CA | Primary Metal Manufacturing331524 | — | ◇ UNVERIFIED |
| KAKeys Aluminum | La Mirada | CA | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| KSKgel Steel, INC | Riverside | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| KMKhemia Metals INC. | Oakland | CA | Primary Metal Manufacturing331491 | — | ◇ UNVERIFIED |
| KLKim Lighting | Ontario | CA | Primary Metal Manufacturing331521 | — | ◇ UNVERIFIED |
| KRKims Roll Up INC | Los Angeles | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| KMKloeckner Metals | Santa Fe Springs | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| KMKloeckner Metals CORP. | City of Industry | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| KMKloeckner Metals Corporation | Fontana | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| KMKloeckner Metals, INC | Tulare | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| KIKuprion, INC. | Fremont | CA | Primary Metal Manufacturing331420 | — | ◇ UNVERIFIED |
| KCKwik Cutting & Grinding | Compton | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| LBLa Bash Metals | Newbury Park | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| LDLansco Die Casting INC | City of Industry | CA | Primary Metal Manufacturing331521 | — | ◇ UNVERIFIED |
| LILarco Industries INC | San Jose | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| LSLarson Steel INC | Gilroy | CA | Primary Metal Manufacturing331111 | — | ◇ UNVERIFIED |
| LHLawson Hughes CO INC | South El Monte | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| LMLb Madole CO INC | Chino | CA | Primary Metal Manufacturing331111 | — | ◇ UNVERIFIED |
| LMLeybold Materials INC | Morgan Hill | CA | Primary Metal Manufacturing331528 | — | ◇ UNVERIFIED |
| LCLGV Coupling, Inc. | Shafter | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| LPLined Pipe Systems LLC | Rancho Cucamonga | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| LCLiska Constructors Dba Aeroforming | Paramount | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| LBListon Brick Company of Corona | Corona | CA | Primary Metal Manufacturing331318 | — | ◇ UNVERIFIED |
| LILixivia INC | Santa Barbara | CA | Primary Metal Manufacturing331313 | — | ◇ UNVERIFIED |
| LILixivia INC | Santa Barbara | CA | Primary Metal Manufacturing331313 | — | ◇ UNVERIFIED |
| LMLoc Mfg INC | San Jose | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| LMLortz Manufacturing Company | Laguna Beach | CA | Primary Metal Manufacturing331513 | — | ◇ UNVERIFIED |
| LALos Angeles Pump and Valve Products, Inc. | Huntington Park | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| LTL to Z Ent INC | Banning | CA | Primary Metal Manufacturing331529 | — | ◇ UNVERIFIED |
| LWLucky Welding & Iron, Sung Chang, Dba | Los Angeles | CA | Primary Metal Manufacturing331222 | — | ◇ UNVERIFIED |
| LPLynwood Pattern | Ontario | CA | Primary Metal Manufacturing331523 | — | ◇ UNVERIFIED |
| MFMacaulay Foundry INC | Berkeley | CA | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
 Machineworks Manufacturing | Chatsworth | CA | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| MGMaggi Gutierrez | Compton | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| MAMagnesium Alloy Prod. CO | Compton | CA | Primary Metal Manufacturing331529 | — | ◇ UNVERIFIED |
| MBMajor Brass Corporation | Gardena | CA | Primary Metal Manufacturing331525 | — | ◇ UNVERIFIED |
| MBMajor Brass Foundry INC | Gardena | CA | Primary Metal Manufacturing331529 | — | ◇ UNVERIFIED |
| MAManhole Adjusting Contractors | Monterey Park | CA | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| MIManrique Ironworks | Spring Valley | CA | Primary Metal Manufacturing331410 | — | ◇ UNVERIFIED |
| MAMarin Airporter | San Rafael | CA | Primary Metal Manufacturing331512 | — | ◇ UNVERIFIED |
| MJMario Juarez-perez | El Cajon | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| MAMaruichi American CORP | Santa Fe Springs | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| MIMas Iron CO | Los Angeles | CA | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| MCMaster Cutting & Engineering INC | Santa Fe Springs | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
 Matthews International Corporation | San Jacinto | CA | Primary Metal Manufacturing331529 | — | ◇ UNVERIFIED |
| MCMehas Construction | Rancho Cucamonga | CA | Primary Metal Manufacturing331315 | — | ◇ UNVERIFIED |
| MCMemry Corporation | Menlo Park | CA | Primary Metal Manufacturing331491 | — | ◇ UNVERIFIED |
| MMMendo Mill Lumber Company | Ukiah | CA | Primary Metal Manufacturing331512 | — | ◇ UNVERIFIED |
| MDMercury Defense Systems INC | Cypress | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
