The Complete Guide to Sheet Metal Fabrication

What Is Sheet Metal Fabrication

Sheet metal fabrication is a manufacturing process that uses metal sheet as the raw material, employing a series of operations—including cutting, forming, joining, and surface treatment—to transform flat plates into structural components such as enclosures, brackets, housings, and frames. Unlike casting or injection molding, which require tooling, sheet metal fabrication enables rapid production without molds. Finished parts offer advantages such as lightweight design, high strength, and excellent heat dissipation, making this process one of the most commonly used manufacturing methods for structural components in industries like electronics, telecommunications, automotive, medical, and automation equipment.

ShowyMetal owns an in-house sheet metal workshop equipped with fiber laser cutting machines, CNC punching machines, an 85T CNC press brake, and welding robots. Our capabilities cover sheet thicknesses from 0.5–6.0 mm, with a maximum cutting area of 1500 × 3000 mm. We support production from single prototypes to low-volume runs and high-volume mass production, providing comprehensive surface treatment and component assembly services including powder coating, anodizing, and electroplating.

Sheet Metal Process Overview

A complete sheet metal part typically requires a combination of multiple processes. The following 12 core processes cover the entire workflow from metal sheet to finished component:

Standard Production Workflow

Typical sheet metal part production is divided into six stages. The process selection in each stage directly impacts final quality, lead time, and cost. Our engineers will confirm the optimal production route with you during the DFM review phase:

Process Details

01 · Fiber Laser Cutting

Fiber laser cutting uses a high-energy-density laser beam to irradiate sheet material, causing the impact point to melt or vaporize instantly. An auxiliary high-pressure gas blows away the molten material, achieving a clean cut. The kerf is narrow, the heat-affected zone is minimal, and the cut surface is smooth, eliminating the need for secondary grinding in most cases.

• Applicable Materials:Carbon steel, stainless steel, aluminum sheet, copper sheet
• Sheet Thickness Range:0.5 – 6.0 mm
• Maximum Sheet Size:1500 × 3000 mm
• Cutting Tolerance:±0.1 mm, narrow kerf, low distortion

Typical Applications: Contour blanking for irregular shapes, perforated plates with dense patterns, and rapid prototyping or short-run production.

02 · CNC Punching

CNC turret punch presses use interchangeable tooling to rapidly punch round holes, square holes, slots, louvers, and stiffening ribs into sheet metal. For parts with regular hole patterns and high production volumes, punching offers significantly lower unit cost compared to laser cutting and can simultaneously perform local forming operations.

• Applicable Materials: Cold-rolled steel (SPCC), galvanized steel (SECC), stainless steel, aluminum sheet
• Sheet Thickness Range:0.5 – 3.0 mm
• Punching Efficiency: Hundreds of strokes per minute, suitable for large-volume production
• Minimum Hole Diameter: Approximately 1 times the sheet thickness

Typical Applications: Electrical enclosure ventilation holes, button holes on equipment panels, cooling louvers, and hole processing for bulk brackets.

03 · CNC Bending

Bending is the core process for sheet metal forming: the upper die presses down, causing the sheet to undergo plastic deformation between the upper and lower dies to achieve the set angle. We utilize an 85T CNC press brake with numerically controlled back gauges and angle control, ensuring high repeatability and excellent consistency across batches.

• Maximum Bending Length:2.5 m
• Bending Angle Tolerance:±0.5°
• Bend Position Tolerance:±0.2 mm
• Minimum Bend Flange: Approximately 6 times the sheet thickness

Typical Applications: Chassis housings, electrical enclosure cabinets, and bending forming for brackets and stiffeners.

04 · Stamping & Forming

For parts with fixed shapes and high demand, tool-based stamping and forming delivers the highest production efficiency and lowest unit cost. Stamping can perform various deformations including blanking, drawing, flanging, and local beading. It is well-suited for combining with bending to create complex three-dimensional shapes.

• Recommended Volume: 1,000+ pieces to amortize tooling costs
• Formable Features: Drawing, flanging, beading, stiffening ribs
• Material Utilization: Up to 80%+ with optimized nesting

Typical Applications: Bowl-shaped parts, covers, clips, and sliding slots requiring tool duplication.

05 · TIG Welding

TIG welding uses an argon gas shield to protect the tungsten electrode and weld pool. The arc is stable, and the weld is fine and dense. Post-weld cleaning is virtually unnecessary, making it the preferred choice for appearance-critical parts and thin sheet welding. It can weld various materials including stainless steel, aluminum, and copper.

• Applicable Sheet Thickness:0.5 – 4.0 mm
• Weld Quality: Dense and uniform, low distortion
• Applicable Materials: Stainless steel, carbon steel, aluminum, copper

Typical Applications: Appearance welds, sealed enclosures, and stainless steel structural components for medical and food processing equipment.

06 · MIG/MAG Welding

MIG/MAG welding uses a CO₂/Ar mixed gas shield with automatic wire feeding. It offers deep penetration, fast welding speeds, and high efficiency, making it the primary process for welding thicker sheet structures. It provides the best cost-effectiveness for thicker carbon steel and stainless steel frame-type parts.

• Applicable Sheet Thickness:1.0 – 6.0 mm
• Welding Efficiency: Approximately 3–5 times that of manual arc welding
• Applicable Materials: Carbon steel, stainless steel (requires dedicated filler wire)

Typical Applications: Welding of load-bearing structures such as frames, bases, and large enclosures.

07 · Spot Welding (Resistance Welding)

Spot welding uses resistive heat to form weld nuggets at the lap joints of sheet metal. No filler wire or shielding gas is required, making it ideal for rapid lap joining of thin sheets. Electrode pressure ensures solid nuggets, with distortion confined primarily to the area surrounding the weld points.

• Applicable Sheet Thickness: 0.5 – 3.0 mm (single layer)
• Weld Strength: Sufficient for general structural connections
• Features: High speed, no consumables required, suitable for automation

Typical Applications: Lap joints for thin sheet enclosures, fixing inner panels of electrical cabinets, and seaming of ventilation ducts.

08 · Robot Welding

Six-axis welding robots automatically complete repetitive welds along predefined paths. Welding speed, angle, and wire feed speed are stable and controllable. For batch production, the weld consistency and visual uniformity are significantly superior to manual welding, while reducing dependence on skilled welders.

• Repeatability: ±0.1 mm
• Applicable Welds: Long straight welds, regular circular/arc welds
• Batch Advantage: Higher volume yields more significant consistency benefits

Typical Applications: Automated welding of high-volume frames, guardrails, pallets, and structural components.

09 · Press Riveting & Embedded Fasteners

The press riveting process embeds components such as threaded inserts, rivets, studs, and nutserts into pre-punched holes under pressure, enabling the sheet metal part to have threads directly ready for fastening. Compared to welding nuts, press riveting prevents deformation, preserves surface coatings, and can be performed after surface treatment.

• Common Embedded Components: Rivet nuts, press rivets, nutserts, standoffs
• Applicable Sheet Thickness: 0.8 – 3.0 mm
• Advantages: Preserves coating, simple assembly, can be installed later in the process

Typical Applications: Electrical cabinet mounting plates, equipment panels, and panel fixing requiring frequent disassembly.

10 · Tapping & Thread Machining

Internal threads are produced by tapping into punched or laser-cut holes, or by directly forming threads using roll taps. Thread rolling produces no chips and increases thread strength, making it a standard machining method for sheet metal connection holes.

• Thread Range: M2 – M8 standard specifications
• Machining Methods: Cutting tap / Rolling tap
• Applicable Sheet Thickness: ≥ 1.0 mm (requires sufficient engagement length)

Typical Applications: Fixing internal support plates, mounting circuit boards, securing heat sinks.

11 · Grinding & Deburring

Laser and press-brake cuts inevitably leave minor burrs and sharp edges. Our deburring processes include vibratory finishing, abrasive belt grinding, and manual finishing, which eliminates assembly safety hazards and provides a clean substrate for surface treatments such as painting and electroplating.

• Treated Areas: Cut edges, punched edges, weld reinforcement
• Methods: Vibratory deburring / Abrasive belt grinding / Brushing
• Quality Requirements: No sharp edges, no snag points, no rust

Typical Applications: A mandatory process before shipping all sheet metal parts; visible aesthetic parts require additional brushing treatment.

12 · Surface Treatment

Surface treatment determines the corrosion resistance and aesthetic finish of sheet metal parts. We offer various processes including powder coating, anodizing, electroplating, brushing, and silkscreen printing. Our complete in-house surface treatment center allows all post-processing to be completed within the same facility, avoiding damage and delivery delays caused by multiple transfers.

• Powder Coating: Film thickness 60–120 μm, rich color options, high corrosion resistance
• Anodizing: Suitable for aluminum parts, can be dyed, high wear resistance
• Electroplating: Zinc plating, chrome plating, electroless nickel plating; provides conductivity and corrosion protection
• Brushing / Silkscreen: Aesthetic decoration and label printing

Further Reading:View the complete surface treatment process guide for detailed parameters and selection recommendations for each process.

Process Comparison Quick Reference

The table below summarizes the application range and characteristics of major sheet metal processes to facilitate rapid evaluation of technical routes in the early stages of your project:

How to Choose the Right Process

Process selection has no single correct answer; it is best evaluated from four dimensions: structural requirements, quantity, appearance, and budget. Recommended paths for common requirements are as follows:

• Structural / Load-bearing Parts (frames, bases): Laser cutting for blanking → CNC bending → MIG welding or robotic welding → Grinding → Powder coating.
• Aesthetic Parts (panels, enclosures): Laser cutting → Bending → TIG welding → Fine grinding and hairline finishing → Painting or anodizing.
• Sealed Enclosures (outdoor electrical cabinets): Laser cutting → Bending → Continuous TIG welding → Pressed inserts → Outdoor powder coating.
• High-Volume Standard Parts: Stamping for blanking and punching → Bending → Spot welding → Automatic painting, offering the lowest per-unit cost.
• Prototype Validation (1–10 pieces): Laser cutting + Bending + TIG welding throughout, no tooling required, fastest delivery within 3 business days.

Frequently Asked Questions

Start Your Sheet Metal Project

Whether you need 1 prototype or 100,000 production units, ShowyMetal’s engineering team can evaluate your process route and provide competitive quotes. Upload your 3D drawings (STEP/IGS/DWG) or 2D drawings (PDF/DXF), and we will respond with a formal quotation including DFM recommendations within 24 hours.