What is Sheet Metal Fabrication?
September 20, 2026
Sheet metal fabrication is a comprehensive cold-working process for metal sheets thinner than 6mm. Its core characteristic is uniform thickness across the part. The process encompasses cutting, forming, joining, and surface treatment, and is widely used to manufacture structural components such as chassis, cabinets, and housings. The frames of food processing machinery, for instance, are predominantly made using this process.
I. Core Process Flow
Blanking (Cutting) → Forming → Joining → Surface Treatment → Assembly & Inspection
II. Detailed Breakdown of Key Processes
1. Blanking (Cutting)
Cutting the sheet into its unfolded profile; the method chosen determines precision and cost:
Shearing: Straight-line cutting using a shear machine; low cost, moderate precision, suitable for simple rectangles.
Laser Cutting: High precision (±0.1mm) and high flexibility; suitable for complex shapes and small batches, but higher cost.
CNC Punching: Using a turret punch press for hole punching, corner cutting, and ribbing; fast speed, suitable for mass production, requires tooling (dies).
Plasma / Waterjet: Plasma for thick plates (>6mm); waterjet causes no thermal deformation, suitable for special materials.
2. Forming
Altering the sheet's shape without compromising its structural integrity:
Bending: Creating V or U shapes using a press brake; the most common method. Requires calculating the developed length (neutral axis K-factor: mild steel 0.4, stainless steel 0.35, aluminum 0.45) and controlling springback (1°–3°).
Stamping/Press Forming: Using a press and dies for deep drawing, embossing, flanging, and louvering; high efficiency, suitable for mass production.
Roll Bending / Rolling: Rolling cylinders or cones using a roll bending machine; used for pipes and tanks.
3. Joining and Fastening
Assembling parts into a structure:
Welding: Spot welding (thin sheets, minimal deformation), Argon arc welding (good aesthetic finish), Laser welding (precision).
Riveting: Blind rivets, self-clinching nuts; allows for disassembly, suitable for thin sheets.
Threaded connections: Bolt/screw assembly; facilitates maintenance.
Bonding: For dissimilar materials or precision parts; requires cleaning and curing.
4. Surface Treatment
Rust prevention, wear resistance, and aesthetics:
Spraying: Electrostatic powder coating (uniform, strong adhesion) and baked enamel; suitable for mass production.
Plating: Zinc (rust prevention), chrome (wear resistance), and nickel (conductivity).
Anodizing: Specific to aluminum; forms a hard oxide layer; dyeable.
Brushing/Passivation: Stainless steel brushing (texture) and passivation (corrosion resistance).
5. Post-processing and Assembly
Deburring, grinding, and leveling; laser marking and adhesive sealing; final assembly and dimensional/visual inspection.
III. Common Materials and Characteristics
Cold-rolled steel sheet (SPCC): Easy to process, low cost; commonly used for chassis and cabinets.
Stainless steel (SUS304/316): Corrosion-resistant, high strength; used for food processing and outdoor equipment.
Aluminum alloy (5052/6061): Lightweight, good conductivity; used for electronics and aerospace housings.
Electro-galvanized sheet (SECC): Zinc-coated for rust prevention; used for electronic chassis.
IV. Application Fields
Electronics: Chassis, cabinets, server housings.
Home appliances: Air conditioner, refrigerator, and microwave oven housings.
Automotive: Body panels and interior components.
Telecommunications: Base station housings and equipment chassis.
Medical: Equipment housings and brackets.
V. Summary
Sheet metal fabrication is a comprehensive cold-working technology for thin sheets, where every step—from blanking to surface treatment—is interconnected. Proper selection of processes and materials enables the manufacturing of structural components that are cost-effective, high-precision, aesthetically pleasing, and durable.
