| 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 |
| 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 |
| MIMasters in Metal, Inc | Oxnard | CA | Primary Metal Manufacturing331523 | — | ◇ 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 |
| MBMetal Briquetting Company | Los Angeles | CA | Primary Metal Manufacturing331529 | — | ◇ UNVERIFIED |
 Metalor Technologies USA | Los Angeles | CA | Primary Metal Manufacturing331419 | — | ◇ UNVERIFIED |
| MRMetal Resources INC | Fontanta | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| MSMetal Sales Manufacturing CORP | Woodland | CA | Primary Metal Manufacturing331318 | — | ◇ UNVERIFIED |
| MRMetech Recycling | Gilroy | CA | Primary Metal Manufacturing331314 | — | ◇ UNVERIFIED |
| MMMichael Miraula | North Hollywood | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| MMMicro Metals | Richmond | CA | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| MFMid-west Fabricating Co, West Bent Bolt | Santa Fe Springs | CA | Primary Metal Manufacturing331222 | — | ◇ UNVERIFIED |
| MCMike Clarksean & Diane Foran | Bakersfield | CA | Primary Metal Manufacturing331318 | — | ◇ UNVERIFIED |
| MIMiranda Iron Works Inc. | Lake Elsinore | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| MMMission Metals | Rialto | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
 M&l Precision Machining INC | Morgan Hill | CA | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| MBMontclair Bronze INC | Montclair | CA | Primary Metal Manufacturing331420 | — | ◇ UNVERIFIED |
| MSMonterey Sculpture Center | Sand City | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| MSM Stephens Mfg INC | Cudahy | CA | Primary Metal Manufacturing331521 | — | ◇ UNVERIFIED |
| MIMtm Industrial | Oceanside | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| MEMvi Engineering & Manufacturing INC | Ontario | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| MAMzd Acquisitions INC Dba Moz Designs INC | Oakland | CA | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| NCNamasco Corporation | Santa Fe Springs | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| NSNanogen Solutions LLC | Hayward | CA | Primary Metal Manufacturing331311 | — | ◇ UNVERIFIED |
| NINanosd INC Energy Nanotechnology R&d | San Diego | CA | Primary Metal Manufacturing331313 | — | ◇ UNVERIFIED |
| NCNational City Foundry | San Diego | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| NRNational Refining CORP | Orange | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| NWNational Wire & Cable CORP | Los Angeles | CA | Primary Metal Manufacturing331222 | — | ◇ UNVERIFIED |
| NSNet Shapes INC | Ontario | CA | Primary Metal Manufacturing331512 | — | ◇ UNVERIFIED |
| NSNet Shapes INC | Ontario | CA | Primary Metal Manufacturing331512 | — | ◇ UNVERIFIED |
| NENew England Lead Burning Co, INC | San Leandro | CA | Primary Metal Manufacturing331314 | — | ◇ UNVERIFIED |
| NRNoranda Recycling INC | San Jose | CA | Primary Metal Manufacturing331000 | — | ◇ UNVERIFIED |
| NTNvent Thermal LLC | Redwood City | CA | Primary Metal Manufacturing331318 | — | ◇ UNVERIFIED |
| OMOlympic Metal Cutting | Montebello | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| OCOntario Castings, Performance Aluminum Products, Reeds Patterns & Molds, R&S ... | Ontario | CA | Primary Metal Manufacturing331524 | — | ◇ UNVERIFIED |
| OEOntario Extrusions, INC. | Ontario | CA | Primary Metal Manufacturing331313 | — | ◇ UNVERIFIED |
| OJOunce Jewelry INC Dba Ounce Collection INC | Los Angeles | CA | Primary Metal Manufacturing331410 | — | ◇ UNVERIFIED |
| PHPacific Handy Cutter INC | Irvine | CA | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| PLPacific Lead Products INC | Vista | CA | Primary Metal Manufacturing331523 | — | ◇ UNVERIFIED |
