Aluminium Brass Bronze Carbon Steel Plastics Stainless Steel

Custom Carbon Steel Fabrication & Manufacturing Services - Custom Metal Fabrication Project Portfolio

Pen Manufacturing provides custom carbon steel fabrication and carbon steel manufacturing services for OEMs, engineers, and procurement teams across the United States. From our AS9100- and ISO 9001-certified facility in Anaheim, California, we machine, form, weld, finish, and assemble carbon steel components for prototype, low-volume, and high-volume production.

Carbon Steel is a tried and true form of metal that we strive for excellence in. By working hand and hand with project designers we have found a way to become top experts in our field. As the top manufacturing company in our region it is safe to say that we provide excellent and creative solutions to any project we accept.

Three decades of shop-floor experience stand behind that claim. Ready to see it applied to your part? Get a Quote and upload your CAD files today.

What Is Carbon Steel Fabrication?

Carbon steel fabrication is the process of cutting, forming, machining, and welding carbon steel — an iron alloy strengthened primarily with carbon — into finished parts and structures. Valued for its strength, weldability, and low cost, carbon steel is the workhorse material of construction, heavy equipment, agriculture, energy, and industrial machinery.

Our carbon steel manufacturing happens entirely under one roof: machining, forming, welding, powder coating, and assembly. One accountable partner, tighter tolerances between operations, and shorter lead times for your program.

Carbon Steel Enclosures & Housings

Carbon steel enclosures deliver the impact resistance and rigidity that industrial environments demand — at a significantly lower material cost than stainless steel. We fabricate custom carbon steel enclosures, control cabinets, equipment housings, machine guards, and panels to your specifications.

Because bare carbon steel will corrode, protection is part of the design conversation from day one. Our in-house powder coating seals and finishes enclosures in a single facility, so parts are protected. And when your environment genuinely calls for stainless, we'll tell you — the right material costs less than the wrong one twice.

Carbon Steel Sheet Metal Fabrication & Forming

From thin-gauge sheet to structural sections, our carbon steel forming capabilities cover shearing, punching, sawing, and press-brake bending — anchored by a 90-ton ironworker and automated cut-off saws on the shop floor. Carbon steel's predictable forming behavior makes it fast and economical to fabricate, and three decades of setup experience keep bend angles and hole positions consistent from first article through repeat production of brackets, frames, weldments, and chassis.

Carbon Steel CNC Machining

Our machining department runs Hurco 4-axis vertical mills with work envelopes up to 50" x 26" x 24", plus a battery of lathes topped by a vertical turret lathe that swings parts up to 54" in diameter. That combination covers precision carbon steel components most shops can't: large housings, machine bases, rings, and heavy turned parts alongside everyday brackets and fittings.

Four-axis machining reduces setups, which protects accuracy. Every critical dimension is verified on calibrated Keyence CMM equipment before shipment.

Carbon Steel Welding, Finishing & Assembly

Carbon steel is the most weldable of the structural metals, and we put six MIG and TIG welding stations behind it — producing structural weldments, frames, and fabricated assemblies with certified welders. After welding, in-house powder coating protects against corrosion, and our assembly services deliver components as ready-to-install units rather than loose parts.

Pen Mfg Offers World-Class Equipment To Assist In Any Custom Carbon Steel Project:

CNC Milling

Hurco VMX50 4-Axis Vertical Mill — 50" by 26" by 24" work envelope

Hurco VMX42 4-Axis Vertical Mill — 42" by 24" by 24" work envelope

Hurco VM3 Vertical Mill — 50" by 18" by 18" work envelope

4 Knee mills

CNC Turning

Vertical turret lathe — 54" round by 24" tall capacity and 50" of swing

Hurco TM10 lathe — 10" chuck

Whacheon lathe — 12" chuck

FEMCO durga lathe — 8" chuck

15" by 120" lathe

12" by 80" lathe

Welding

6 MIG and TIG welding stations

Cobramatic aluminum "Push-Pull" station

Cutting & Forming

Automatic cut-off/band saw

90-ton ironworker

1 HYD-MECH miter saw

Material Handling & Support

3-ton bridge crane

Support equipment — Including fork lifts and hand grinders

What this means for your project: work envelopes and swing capacities large enough for oversized parts, enough spindles and welding stations to run volume without bottlenecks, and a 3-ton bridge crane to handle heavy weldments safely.

Why Choose Carbon Steel for Your Components?

Cost-effectiveness

The most economical structural metal per pound of strength, which is why it dominates industrial fabrication budgets.

Strength and durability

High tensile strength and impact resistance for frames, guards, and load-bearing parts.

Weldability

Joins readily with MIG and TIG processes, ideal for large weldments and structural assemblies.

Machinability

Mild and medium-carbon grades cut fast and predictably, keeping per-part machining costs down.

Versatility

Available from thin sheet to heavy plate, bar, and structural shapes for nearly any geometry.

Finish-ready

Takes powder coating exceptionally well for corrosion protection and a professional appearance.

Industries We Serve

U.S. manufacturers specify our carbon steel fabrication for construction, heavy equipment, transportation, agriculture, energy, industrial machinery, infrastructure, and material handling. Typical work includes structural frames, equipment bases, machine guards, brackets, weldments, and enclosures — parts where strength, durability, and cost control decide the bill of materials.

Why U.S. Manufacturers Choose Pen Manufacturing

Carbon steel work rewards a shop that has seen everything. Here is what you get with ours:

Decades of fabrication experience

30+ years of machining, forming, and welding steel for customers whose equipment cannot sit idle waiting on parts.

Aerospace-grade quality on industrial parts

AS9100 and ISO 9001 certification means even a simple bracket runs through a disciplined quality system.

Documented four-step quality control

engineering preparation up front, certified fabrication, inspection during the run, and final validation on Keyence CMM and calibrated metrology.

One roof, zero hand-offs

machining, forming, welding, powder coating, and assembly in a single Anaheim, California facility.

Volume flexibility

the same equipment and quality system carries your carbon steel components from prototype through high-volume production.

Built in the USA, delivered on time

responsive communication and dependable scheduling for OEMs nationwide.

From Prototype to Production: How It Works

Send your RFQ

Upload CAD files (STEP, DWG, DXF, IGES, STL, or PDF) and requirements through our quote form, or call 714-992-0950.

Engineering preparation

We extract critical dimensions, define quality metrics, and work hand in hand with your designers — using 3D modeling and prototypes to catch issues before they cost money.

Certified fabrication

Machining, forming, and welding run under our AS9100/ISO 9001 system with verified in-process inspection.

Validation and delivery

Keyence CMM and calibrated metrology confirm every critical dimension; parts are powder coated, assembled as required, and shipped on schedule.

Start Your Carbon Steel Project Today

From a one-off machined prototype to high-volume fabricated assemblies, Pen Manufacturing delivers carbon steel components backed by 30+ years of experience, world-class equipment, and AS9100/ISO 9001 certified quality.

Get a Quote → — Upload your CAD files for a fast, detailed quotation. Want an engineer's eyes on your design first? Call 714-992-0950.