Precision Stainless Steel Fabrication & Custom Enclosures - Custom Metal Fabrication Project Portfolio

Pen Manufacturing delivers precision stainless steel fabrication, custom stainless steel enclosures, and CNC machining services for OEMs, design engineers, and procurement teams across the United States. From our AS9100- and ISO 9001-certified facility in Anaheim, California, we fabricate, machine, weld, finish, and assemble custom stainless steel parts in more than a dozen grades — from a first prototype to repeat high-volume production.

When corrosion resistance, strength, and hygiene are non-negotiable, material experience matters. Our team has spent more than three decades fabricating metals for aerospace, medical, food processing, and industrial customers who cannot afford a part that fails. Ready to put that experience to work? Get a Quote and upload your CAD files today.

Stainless steel fabrication is the process of cutting, forming, machining, and welding stainless steel sheet, plate, bar, or tube into finished components. Because stainless steel combines high strength with exceptional corrosion resistance, fabricated stainless parts are the standard in food and beverage, medical, aerospace, energy, and marine applications where failure is not an option.

At Pen Manufacturing, every step happens under one roof. That single-source approach keeps tolerances tight between operations, shortens lead times, and gives you one accountable partner instead of three.

Stainless steel enclosures protect sensitive equipment in environments that would destroy lesser materials: washdown zones on food processing lines, sterilization areas in medical facilities, corrosive coastal and outdoor installations, and high-heat industrial settings.

We build custom stainless steel enclosures, housings, cabinets, and panels to your exact specifications — typically in 304/304L for sanitary applications, or 316/316L where chlorides and aggressive cleaning chemicals are present. Continuous welded seams, clean cosmetic finishes, and accurate hardware placement come standard, whether you need one enclosure or a thousand.

Our stainless steel sheet metal capabilities include precision cutting, CNC punching, press-brake forming, hardware insertion, and welding. Stainless behaves differently than mild steel on the shop floor — it work-hardens quickly and springs back more during bending — so accurate parts depend on experienced setup and the right tooling. Three decades of forming stainless means your panels, brackets, guards, and chassis arrive with consistent bend angles and hole positions from first article through full production.

Stainless steel is tougher on tooling than aluminum: it cuts slower, generates more heat, and work-hardens if feeds and speeds are wrong. Our stainless steel CNC machining services are built around that reality, with rigid setups and machining parameters proven across grades like 304, 316, 17-4 PH, and 17-7 PH.

We mill and turn custom stainless steel parts to tight tolerances, then verify critical dimensions on calibrated Keyence CMM equipment before shipment. Prototypes, fixtures, and production runs all follow the same documented quality process.

Welding stainless steel well means controlling heat. Excess heat input can distort thin sections and degrade the corrosion resistance that made you choose stainless in the first place. Our certified welders use TIG and MIG processes tuned for stainless, and for weld-intensive designs we often recommend low-carbon L-grades (304L, 316L) that better preserve corrosion performance at the weld zone.

After fabrication, in-house finishing — including powder coating — and assembly services mean your components can arrive as clean, ready-to-install units.

We pride ourselves on our industry experience and unparalleled skills to custom fabricate, machine, and weld stainless steel material in the below types and grades:

300 Series (Including But Not Limited To)

Not sure which grade your part needs? Send us your drawings and operating environment, and our engineers will recommend the most cost-effective grade that meets your corrosion, strength, and temperature requirements.

U.S. manufacturers specify our stainless steel fabrication for aerospace and defense structures, medical devices, food and beverage processing equipment, energy and refinery systems, transportation, industrial equipment, electronics, and infrastructure. Because grade selection drives performance in each of these industries, we match the alloy, weld process, and finish to your application's standards — not the other way around.

Switching or selecting a stainless steel fabricator carries real program risk. Here is how we take that risk off the table:

From a single machined prototype to thousands of fabricated enclosures, Pen Manufacturing delivers custom stainless steel parts backed by 30+ years of experience and AS9100/ISO 9001 certified quality.

Get a Quote → — Upload your CAD files for a fast, detailed quotation. Prefer to talk through your application first? Call 714-992-0950.

We pride ourselves on our industry experience and unparalleled skills to custom fabricate, machine, and weld stainless steel material in the below types and grades: