Custom Steel Frames and Weldments: Fabrication, Welding, and Precision Machining Under One Roof / South Korea
For automation OEMs and machine builders, the structural frame is the part nobody talks about until it's late. It's heavy, expensive to ship, hard to inspect remotely, and one of the few components where weld quality and flatness directly determine whether the rest of your machine works.
Belinker, a Korean precision manufacturer with a U.S. subsidiary in Illinois, fabricates, welds, and machines structural steel frames and weldments for machine builders, automation OEMs, and industrial equipment manufacturers — the entire process under one roof, with no farmed-out welding and no surprise dimensional issues on the machined surfaces.
The frames shown here are typical of what we ship: large welded steel structures up to several meters long, with critical mounting surfaces machined flat after welding, ready for component installation.
What We Build
Machine bases and equipment frames
Welded steel weldments for automation systems
Structural frames for industrial machinery
Robotic cell platforms and conveyor frames
Skid bases for OEM equipment
Custom fabricated enclosures and housings
Sizes from 500 mm benchtop frames up to 6+ meter machine bases. Single-unit prototypes through small-series production.
Steel Fabrication
We work from your drawings — 3D models or 2D prints, plus weld symbols and inspection callouts. In-house capabilities:
Plasma and laser cutting for plate up to 25 mm
CNC press brake forming up to 3 meters
Saw cutting for structural shapes (angle, channel, square tube, I-beam)
Drilling, tapping, and hole prep before welding
Material handling for plates and beams up to several tons
Welding
All welding done in-house by certified welders. Processes:
GMAW (MIG) — primary process for carbon steel structural work
GTAW (TIG) — stainless steel, aluminum, and any application requiring clean welds
FCAW — heavier sections and thick-plate joints
Welder qualification per AWS D1.1 (carbon steel) and AWS D1.2 (aluminum). Weld procedure specifications (WPS) and procedure qualification records (PQR) available on request.
For frames that need to hold dimensional tolerance after welding, we use:
Custom welding fixtures designed for your specific frame
Stress relief (heat treatment) before final machining when distortion risk is high
Sequenced welding to minimize warp
Pre- and post-weld inspection
Post-Weld Machining — Where It Matters
This is the capability that separates us from a typical fab shop.
After a frame is welded, the mounting surfaces — where motors, linear rails, bearings, or precision components install — need to be flat, parallel, and dimensionally accurate. Most fab shops weld it and ship it. We bring the welded frame onto our CNC machining centers and finish the critical surfaces in-house:
Surface milling for flatness and parallelism
Precision hole patterns for mounting (drilling, tapping, reaming, boring)
Dowel holes and locating features
Counterbores for cap screws
Typical capabilities:
Flatness: 0.05 mm over 1 m on machined surfaces
Hole position tolerance: ±0.05 mm
Tapped hole quality verified with go/no-go gauges
Large-part capacity: up to 2,000 mm × 1,000 mm × 800 mm
You receive a frame that's already trued up — no second-vendor routing, no shimming and grinding on your shop floor.
Materials
Carbon steel — A36, A572 Gr 50, S355
Stainless steel — 304, 316/316L
Structural aluminum — 6061-T6 (plate, extrusion, tube)
Tool steel for wear-resistant surfaces
ASTM, AISI, and JIS designations. Mill certificates with every shipment.
Surface Finishing
Built into the project, not bolted on after:
Sandblasting (SSPC-SP6 to SP10)
Powder coating
Wet paint to customer color spec
Zinc-rich primer for export packaging
Pickling and passivation for stainless
Why It Matters for OEMs
Most U.S. machine builders today are sourcing fabrication from one shop, welding from another, and machining from a third. The frame ships back and forth, dimensions drift, and the lead time stretches. Or they're using a single domestic shop that won't take low-volume work — and a prototype frame quotes at $18K with a 12-week lead time.
Belinker consolidates the full chain — fabrication, welding, post-weld machining, and finishing — into a single supplier. You send the drawing, we send back a finished frame. One unit, five units, or fifty. High-mix, low-volume is what we're built for.
How to Get Started
Send us:
Drawing (PDF) and 3D model (STEP preferred)
Material spec
Welding requirements (AWS standard, inspection level)
Machining callouts on critical surfaces
Quantity and target delivery date
We respond to RFQs in 1–3 business days with a real quote — material breakdown, fabrication hours, machining hours, finishing, and freight. NDA before drawing review is standard.
Frames are heavy, costly, and unforgiving when they arrive wrong. We take that seriously — and we'd be glad to quote your next one!