| Korzan Enterprises Inc Milling, Turning, Waterjet, Welding, EDM, Grinding, Finishing | Orchard Park, NY | MillingTurningWaterjetWeldingEDMGrindingFinishing | - |
| Kosmo Machine Inc Milling, Turning, Welding, Casting, EDM | Sandston, VA | MillingTurningWeldingCastingEDM | - |
| KP Manufacturing Milling, Casting, Finishing, Assembly | Spencer, IA | MillingCastingFinishingAssembly | - |
| Kriewall Enterprises Inc Milling, Laser, Welding, Stamping, EDM, Finishing · ISO 9001 | Romeo, MI | MillingLaserWeldingStampingEDMFinishing | ISO 9001 |
| Kte Holdings LLC Milling, Turning, Welding, Grinding, Finishing | Mableton, GA | MillingTurningWeldingGrindingFinishing | - |
| KV Engineering LLC Milling, Turning, Laser, Waterjet, Welding | Miami, FL | MillingTurningLaserWaterjetWelding | - |
| L.F. Industries, Inc Milling · ISO 9001, AS9100 | Carlsbad, CA | Milling | ISO 9001, AS9100 |
| L&B Labs Milling, Turning, Laser, Welding, EDM, Grinding | San Jose, CA | MillingTurningLaserWeldingEDMGrinding | - |
| La Gauge Co Milling, Turning, EDM, Grinding, Finishing · ISO 9001, AS9100, ITAR | Sun Valley, CA | MillingTurningEDMGrindingFinishing | ISO 9001, AS9100, ITAR |
| Lakehouse Industries Milling, Turning, Finishing | Woodland, WA | MillingTurningFinishing | - |
| Lakes Area Manufacturing Co Milling, Grinding | Shafer, MN | MillingGrinding | - |
| Lakeside Innovative Technologies Milling, Turning, Finishing · ISO 9001, ITAR | Chittenango, NY | MillingTurningFinishing | ISO 9001, ITAR |
| Lamjen Inc Milling, Turning, Welding, Stamping, Casting · ISO 9001 | Erie, PA | MillingTurningWeldingStampingCasting | ISO 9001 |
| Lancaster Design & Machine Milling, Welding, Grinding · ISO 9001 | Dacula, GA | MillingWeldingGrinding | ISO 9001 |
| Land Sea Air Manufacturing Inc Milling, Turning, Waterjet, Assembly | Westminster, MD | MillingTurningWaterjetAssembly | - |
| Lange Grinding & Machining, Inc Milling, Turning, Welding, Grinding | Streetsboro, OH | MillingTurningWeldingGrinding | - |
| Langley Industrial Machining Milling, Turning, Laser, Punching, Welding, Stamping, Finishing · ISO 9001 | Sharpsburg, NC | MillingTurningLaserPunchingWeldingStampingFinishing | ISO 9001 |
| Lanzen Inc Milling, Laser, Welding | Bruce Twp, MI | MillingLaserWelding | - |
| Laser Craft Technologies Inc Milling, Turning, Laser, Punching, Bending, Welding, Assembly · ISO 9001 | Gainesville, GA | MillingTurningLaserPunchingBendingWeldingAssembly | ISO 9001 |
| Laser Cutting Co Milling, Laser, Bending, Welding, Grinding, Finishing · ISO 9001 | Harrison Township, MI | MillingLaserBendingWeldingGrindingFinishing | ISO 9001 |
| Latitude Corp Milling, Waterjet, Punching, Bending, Welding, Stamping, Grinding, Finishing · AS9100 | Verona, WI | MillingWaterjetPunchingBendingWeldingStampingGrindingFinishing | AS9100 |
| Latva Machine, LLC Milling, Turning, Stamping, Casting, Forging, Finishing · ISO 9001 | Newport, NH | MillingTurningStampingCastingForgingFinishing | ISO 9001 |
| Lawson Precision Machining, Inc Milling, Turning, Welding, Grinding · ISO 9001 | Bucyrus, OH | MillingTurningWeldingGrinding | ISO 9001 |
| Layne West Manufacturing LLC Milling, Swiss, Welding, Grinding | Boise, ID | MillingSwissWeldingGrinding | - |
| LD Redmer Milling, Turning, Swiss, Welding, Finishing · ISO 9001, ITAR, NADCAP | Bensenville, IL | MillingTurningSwissWeldingFinishing | ISO 9001, ITAR, NADCAP |
| Lean Industrial LLC Milling, Casting, Grinding · ISO 9001 | Eugene, OR | MillingCastingGrinding | ISO 9001 |
| Leanwerks, LLC Milling, Turning, Welding, Casting, Grinding, Assembly · ISO 9001, AS9100, ITAR, CMMC | Ogden, UT | MillingTurningWeldingCastingGrindingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Lear Machining & Waterjet Inc Milling, Turning, Waterjet, Welding, Grinding · ISO 9001 | Columbus, IN | MillingTurningWaterjetWeldingGrinding | ISO 9001 |
| Leister Machine LLC Milling, Welding | Bedford, PA | MillingWelding | - |
| Lemmatic Precision LLC Milling, Turning, Finishing · ISO 9001, ITAR | American Fork, UT | MillingTurningFinishing | ISO 9001, ITAR |
| Lewis Precision & CNC Inc Milling, Turning, Bending, Welding, Grinding, Finishing · ISO 9001, AS9100 | Theodore, AL | MillingTurningBendingWeldingGrindingFinishing | ISO 9001, AS9100 |
| LG Metalworks LLC Milling, Turning, Laser, Waterjet, Welding, EDM, Finishing | Bloomington, IN | MillingTurningLaserWaterjetWeldingEDMFinishing | - |
| LHM Engineering LLC Milling, Swiss, Laser, Waterjet, Stamping, EDM, Grinding, Finishing, Assembly · ISO 13485 | Manchester, MA | MillingSwissLaserWaterjetStampingEDMGrindingFinishingAssembly | ISO 13485 |
| Liberty CNC LLC Milling, Turning, Finishing · ISO 9001 | Cocolalla, ID | MillingTurningFinishing | ISO 9001 |
| Liberty Hill Company Milling, Turning, Swiss, Laser, Waterjet, Bending, EDM · ISO 9001, AS9100, ITAR | Huntington, WV | MillingTurningSwissLaserWaterjetBendingEDM | ISO 9001, AS9100, ITAR |
| Liberty Tool Inc Milling, Turning, Welding, Grinding · ISO 9001, AS9100, ITAR | Sterling Heights, MI | MillingTurningWeldingGrinding | ISO 9001, AS9100, ITAR |
| Lightning Aerospace LLC Milling, Turning, Bending, Assembly · ISO 9001, AS9100, ITAR | Park City, KS | MillingTurningBendingAssembly | ISO 9001, AS9100, ITAR |
| Lightsout CNC Manufacturing Company Milling · ISO 9001, ITAR, NADCAP, ISO 13485, CMMC | Beverly Hills, CA | Milling | ISO 9001, ITAR, NADCAP, ISO 13485, CMMC |
| Limestone Manufacturing LLC Milling, Turning, Laser, Bending, Welding, Metal AM, EDM, Grinding · ISO 9001, AS9100 | Somerset, KY | MillingTurningLaserBendingWeldingMetal AMEDMGrinding | ISO 9001, AS9100 |
| Lindor Tool, Inc Milling, Turning, Welding, Casting, Grinding | Saint Croix Falls, WI | MillingTurningWeldingCastingGrinding | - |
| Linear Machining Technology LLC Milling, Turning, EDM, Grinding, Finishing · ISO 9001 | Irwin, PA | MillingTurningEDMGrindingFinishing | ISO 9001 |
| LNP Machining Milling, Turning, Welding, Finishing · ISO 9001, AS9100, ITAR, ISO 13485 | San Jose, CA | MillingTurningWeldingFinishing | ISO 9001, AS9100, ITAR, ISO 13485 |
| Long Machine Milling, Turning, Grinding | Temecula, CA | MillingTurningGrinding | - |
| Loutech LLC Milling, Turning, Swiss, Finishing · ISO 9001, AS9100, ITAR | Chino, CA | MillingTurningSwissFinishing | ISO 9001, AS9100, ITAR |
| Lowery's Job Shop Milling, Turning, Laser, Welding, Grinding, Finishing | Saint Louisville, OH | MillingTurningLaserWeldingGrindingFinishing | - |
| LP Precision, Inc Milling, Turning, Grinding, Finishing | Santa Clara, CA | MillingTurningGrindingFinishing | - |
| LT CNC Machining Inc. Milling, Turning, Welding · AS9100 | San Diego, CA | MillingTurningWelding | AS9100 |
| Ltmt Machining LLC Milling, Finishing | Santa Clara, CA | MillingFinishing | - |
| Luna's Sheet Metal Inc Milling, Turning, Bending, Laser, Welding | Santa Clara, CA | MillingTurningBendingLaserWelding | - |
| LV Swiss Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001, AS9100, ITAR, ISO 13485 | La Verkin, UT | MillingTurningSwissGrindingFinishing | ISO 9001, AS9100, ITAR, ISO 13485 |