Sheet Metal and Welding: Practical Guide for OEM Fabrication Projects

Introduction to Sheet Metal and Welding in OEM Manufacturing

Between 2024 and 2026, sheet metal and welding have become even more central to OEM manufacturing. The shift toward electric vehicles demands battery enclosures that combine structural integrity, hermetic sealing, and crash safety. Medical device makers need sterilizable, corrosion-resistant housings with smooth finishes. Aerospace and robotics programs require thin-gauge metal parts shaped to exact tolerances for weight savings without sacrificing strength.

Sheet metal fabrication involves bending and cutting thin metal sheets into individual components, while welding is the downstream step that permanently fuses those components into functional assemblies. Welding creates strong, permanent joints between sheet metal parts, minimizing the need for mechanical fasteners in most applications. The primary sheet metal welding methods used by modern OEMs include gas metal arc welding (MIG), tungsten inert gas welding (TIG), resistance spot welding, plasma arc welding, and laser welding.

Anebon Metal Products Limited, an ISO 9001:2015 and ISO 14001:2015 certified manufacturer based in Dongguan, China, has served overseas OEMs since 2010 with integrated fabrication and welding capabilities. This article focuses on the practical choices engineers face during every welding project: process selection, material pairing, sheet metal welding techniques, and how to source reliable solutions from a capable partner.

What Is Sheet Metal Fabrication vs. Welding?

These two disciplines work together but serve distinct roles in producing finished metal parts.

Sheet metal fabrication covers the full upstream process chain:

• DFM review and flat pattern design

• CNC laser cutting, punching, or plasma cutting

• CNC bending and forming on press brakes

• Hardware insertion (threaded inserts, rivets, PEM fasteners)

• Surface finishing (powder coat, plating, anodizing)

Welding is the set of joining fabrication processes that permanently fuse fabricated metal pieces into sub-assemblies or final products. Welding is used to join pre-cut and pre-bent sheet metal pieces into structural components such as server chassis, battery trays, and medical device frames. It is the preferred method for creating a permanent bond between sheet metal parts.

Because sheet metal is typically thin and can warp or distort during welding, OEMs often prefer a single supplier handling both fabrication and welding. This approach avoids tolerance stack-up across vendors and simplifies accountability.

Types of Welding Used for Sheet Metals

Selecting the right welding technique is critical for achieving high-quality results in metal fabrication. Here are the primary types of welding relevant to thin-gauge metal sheets (roughly 0.2–6.0 mm):

• MIG (GMAW): gas metal arc welding using a continuous solid wire electrode and shielding gas; versatile for steel and aluminum

• TIG (GTAW): gas tungsten arc welding with a non consumable tungsten electrode; best for precision and clean welds

• Resistance spot welding: electric current through copper electrodes fuses overlapping thin sheets in milliseconds

• Plasma arc welding: a constricted electric arc variant of TIG, faster and suitable for automation

• Laser welding: high energy density for minimal distortion and high precision on complex assemblies

• Electron beam welding: used in specialty aerospace applications requiring deep penetration in vacuum

The metal arc welding family (MIG, shielded metal arc welding / stick welding, flux-cored) handles high-volume structural work, while high-precision processes (TIG, laser) serve cosmetic and critical-integrity joints. Material thickness influences the choice of welding process, as does production volume and appearance requirements. Anebon works with multiple different welding methods and helps OEMs pick the most cost effective technique at the RFQ stage.

Gas Metal Arc Welding (MIG) for Sheet Metal

MIG welding uses a metal inert gas process where a continuous metal wire electrode is fed through a welding gun into the weld area. The electric arc between wire and workpiece melts both filler material and base metal, while shielding gas (typically 75% argon / 25% carbon dioxide for steel) protects the weld pool from contamination. This welding process involves feeding the wire automatically, making it efficient for production runs.

MIG welding is ideal for thin sheet metal and is suitable for aluminum, steel, and stainless steel. Typical OEM uses include carbon steel brackets from about 1.0 mm up to 8.0 mm, HVAC cabinets, and industrial enclosures.

Advantages:

• High deposition rate and welding speed

• Relatively easy to automate with robotic cells

• Cost-effective for medium to high volumes

• Good for fillet welds on box assemblies

Limitations:

• Risk of burn through on thin materials below ~0.8 mm if parameters are not optimized

• Wider heat-affected zones than TIG or laser

• More spatter cleanup may be needed

Tungsten Inert Gas (TIG) Welding for Precision Sheet Metal

TIG welding uses a tungsten electrode that does not melt during the welding process. The welder controls the arc while manually adding a separate filler metal rod when needed. An inert shielding gas, usually pure argon, flows around the weld puddle to prevent oxidation.

TIG welding provides high precision for thin materials and is ideal for non ferrous metals like titanium and copper. It delivers superior weld quality on thin sheets down to approximately 0.6 mm and produces high quality welds with minimal spatter.

Concrete applications include:

• Medical device housings in 304/316L stainless steel requiring hospital-grade surface finish

• Aerospace sensor brackets where fatigue performance and corrosion resistance are critical

• High-end electronics bezels where weld seams must be nearly invisible

TIG welding methods involve slower travel speeds and require higher operator skill, making the cost per weld higher than MIG. But for applications where cosmetic quality, integrity, and clean welds on various materials are non-negotiable, these tig welding methods are the standard choice among different welding processes.

Resistance Spot Welding and Other Sheet Metal Welding Methods

Several secondary sheet metal welding methods serve specific OEM needs:

• Resistance spot welding: Copper electrodes clamp overlapping sheets (typically 0.8–2.0 mm steel), passing electric current to create localized fusion. Spot welding is commonly used in automotive manufacturing for body-in-white panels and appliance enclosures, with production lines running 400–600 robots per line.

• Seam and projection welding: Resistance variants for leak-tight seams in tanks or attaching nuts and studs to sheet metal surfaces.

• Plasma arc welding: A higher-energy cousin of TIG, plasma arc welding is faster and more precise than TIG welding and is suitable for both thin and thick metals. It excels on stainless and nickel alloys in automated setups.

• Laser welding: Offers pinpoint accuracy for complex materials with very narrow heat-affected zones. Capital cost is higher, but laser robotic welding for EV battery enclosures increased ~35% year-over-year in 2025.

• Stick welding (shielded metal arc welding): Effective for tough metals like iron and steel, versatile and can be used in any position, and suitable for thick materials and thicker materials in field conditions. While less common for thin sheet metal, stick welding remains a fundamental process for structural steel and repair work.

• Gas welding: An older method using fuel gas and oxygen; largely replaced by arc welding processes in production but still used for certain brazing and repair tasks.

Core Welding Positions for Sheet Metal Assemblies

Welding position affects the selection of welding methods and directly impacts quality and cost on fabricated assemblies.

• Flat position: Most productive. Gravity keeps molten metal in the weld pool. Used for base panels, large sheet seams, and frame welding. Best control for both MIG and TIG.

• Horizontal position: Welding on vertical surfaces where the weld puddle tends to sag slightly. Requires parameter tuning (slower speed, adjusted current) for sidewalls of cabinets and machine guards.

• Vertical position: Welding upward or downward on tall enclosures or large frames. Pulsed MIG or controlled stick settings help manage the weld pool against gravity.

• Overhead position: The most challenging-gravity pulls molten metal downward. Reserved for situations where part repositioning is impossible.

Anebon designs fixtures and jigs to rotate parts whenever possible so welds can be completed in the flat or horizontal position, improving consistency and reducing cost.

Key Welding Techniques to Protect Thin Sheet Metals

Common challenges in welding thin sheet metal include warping and burn through. Several practical sheet metal welding techniques address these problems on gauges from 0.6 to 2.0 mm:

• Tack welding: Tack welding temporarily holds metal pieces in place before applying a final weld. Small tacks spaced along the joint lock alignment and reduce fixturing slippage.

• Skip welding: Intermittent welds spaced along a seam spread the heat load over time. Short welds or stitch welds minimize distortion on thin sheet metal during welding.

• Stitch welding: Short weld segments with gaps, used where full-length welds are not structurally required, keeping heat input low.

• Travel speed and arc control: Correct torch welding speed, proper arc length, and avoiding wide weaving patterns are critical. Stringer beads produce less distortion than weave beads on thin materials.

Shielding Gas Selection for Gas Metal Arc and TIG Welding

Shielding gas protects the weld pool and heat-affected zone from atmospheric contamination that causes porosity and embrittlement.

• MIG on carbon steel: Argon/CO₂ blends (75/25) balance arc stability, penetration, and cost. Pure carbon dioxide is cheaper but increases spatter.

• TIG on stainless, aluminum, titanium: Pure argon maintains a narrow, stable arc. Argon acts as the primary inert gas for most TIG applications.

• Aluminum plate: Helium or argon/helium mixes provide deeper penetration and higher travel speeds on highly conductive thicker materials.

Anebon standardizes gas choices for repeatability across production runs but adjusts shielding gas blends based on OEM specifications and specific weld procedures.

Material Choices and Weldability in Sheet Metal Projects

Different materials behave differently under the heat that welding involves heating two metals together:

• Low-carbon and mild steel: Carbon steel is the most economical choice for sheet metal welding. Welds well with MIG and spot welding. Galvanized coatings complicate welding (zinc vapor, porosity) and require post-weld corrosion protection.

• Stainless steel (304, 316L): Excellent corrosion resistance. TIG and MIG both work, but heat tint must be controlled. Matching filler metal (308/316 filler) prevents sensitization.

• Aluminum alloys (5052, 6061): Lightweight and corrosion-resistant, but high thermal conductivity demands careful heat management. Aluminium requires AC welding for pure forms and DC for alloys. Risk of burn through on thin sheets is elevated.

• Specialty metals: Copper, brass, and titanium appear in electronics, medical, and aerospace custom sheet metal applications. These non ferrous metals demand controlled welding procedures-titanium, for example, is reactive with oxygen at high temperatures and requires inert atmosphere or vacuum. Each has a different melting point and thermal behavior requiring edge preparation and careful technique.

Design for Manufacturability (DFM) in Welding Sheet Metal

DFM starts at the RFQ stage, before designs are frozen. Early feedback prevents costly rework. OEM customers often require tight tolerances in custom metal parts production, making DFM critical.

• Keep joint designs simple: lap and fillet welds over complex groove or corner joints on thin sheet metal

• Use consistent material thicknesses across joints to avoid stress concentrations

• Include tab-and-slot features and locating holes so fixtures and robots can position metal parts accurately into the desired shape

• Consider weld access-the welding gun needs clear path to the joint

Anebon’s engineers provide early DFM feedback on 3D models and drawings (SolidWorks, STEP files), reducing welding time and rework before production starts.

Controlling Distortion and Heat in Sheet Metal Welding

Distortion is the primary enemy when welding sheet metal. Practical controls include:

• Backing bars and heat sinks: Copper or aluminum bars clamped behind weld joints draw away excess heat, protecting flatness

• Weld sequence planning: Welding from center outward and alternating sides balances residual stresses across the assembly

• Smaller consumables: Smaller wire diameters, lower current settings, and pulsed welding modes reduce heat input on light-gauge materials

• Post-weld checks: Anebon verifies flatness and dimensional tolerances using straightedges, gauges, and CMMs where tight-tolerance OEM parts demand it

Integrating Welding With CNC Machining and Other Processes

Many welded sheet metal assemblies include CNC machined components-precision mounting blocks, heat sinks, threaded inserts-that must be joined without distorting machined features.

A common process flow looks like this: CNC laser cutting → bending → welding → CNC machining of critical faces and holes → surface finishing. This sequence lets you weld first, then machine datum surfaces to final tolerance.

Anebon also offers die casting and CNC machining, allowing OEMs to combine cast, machined, and sheet metal parts in one welded assembly. Datum schemes and tolerance stacks across welded and machined features must be carefully planned to ensure interchangeability in volume production.

Quality Assurance in Sheet Metal Welding Services

Quality assurance ensures weld integrity and reduces defects across every production run. ISO 9001:2015 certification indicates a commitment to quality assurance, and quality assurance helps in maintaining compliance with industry standards.

Key QA practices for sheet metal welding services include:

• Visual inspection to standards like ISO 5817 for weld appearance, size, and penetration

• Dimensional checks with gauges and CMMs

• Dye penetrant or radiographic testing where specified (medical, aerospace, pressure applications)

• Documented Welding Procedure Specifications (WPS) and welder qualifications

• Full traceability of materials, weld parameters (current, voltage, shielding gas flow), and batch records

Quality assurance processes improve overall production efficiency, and effective quality assurance can enhance customer satisfaction significantly. Anebon’s ISO 9001:2015 system and documented work instructions maintain consistent weld quality across long production runs.

Typical Industries and Applications for Sheet Metal Welding

Welded sheet metal serves industries ranging from aerospace to consumer electronics:

• Aerospace: Avionics boxes, instrument brackets, sensor mounts-often TIG welded in specialty alloys with tight distortion budgets

• Medical devices: Cart frames, sterilizable housings in 316L stainless-TIG for visible, smooth seams

• Automotive and EV: Battery enclosures, structural brackets, cross members. Friction stir welding has become standard for aluminum battery trays, achieving less than 0.5 mm distortion across meter-scale surfaces

• Electronics: Rack-mount chassis and telecom enclosures-spot welding or MIG for structural seams, TIG for visible panels

• Robotics and industrial machinery: Machine guards, sensor mounts, heavy frames-MIG for cost efficiency, TIG or laser where aesthetics matter

A typical welding project timeline runs: RFQ → DFM review (1–2 days) → prototype (3–4 weeks) → fixture build → first article inspection → pilot → full production. Anebon supports both rapid prototyping in small batches and scaling to stable, repeatable production.

Choosing a Sheet Metal Welding Partner

When evaluating sheet metal welding services, use this checklist:

• Process range: Verify MIG, TIG, spot, laser, and plasma capabilities for your welding method needs

• Material experience: Confirm work with aluminum, stainless steel, carbon steel, copper, and specialty alloys

• DFM support: Assess responsiveness during quoting and ability to suggest cost-saving alternatives

• Certifications: ISO 9001 and ISO 14001 are baseline; look for documented weld procedures and traceability

• Communication: English-speaking engineering staff, digital progress updates, and structured APQP/PPAP support matter for overseas OEM supply chains

Cost, Lead Time, and Efficiency Considerations

Different welding processes carry different cost profiles:

Method	Relative Cost	Speed	Best For
MIG / Spot	Lower	High	Volume production, structural joints
TIG	Higher	Slower	Cosmetic, thin-gauge, critical joints
Laser	High capital	Very high	Automated lines, minimal distortion

Joint design simplification, fixture reuse, and standardized materials reduce setup time and per-part cost. Anebon can provide alternative quotes-for example, MIG vs TIG on the same assembly, or different gauge options-so engineers can balance appearance, strength, and budget. Early engagement before designs are frozen typically yields the largest savings in weld time and material usage.

Working With Anebon Metal Products for Sheet Metal Welding

Anebon brings precision sheet metal fabrication, multiple welding techniques, CNC machining, die casting, surface treatments, and assembly under one roof in Dongguan. With ISO 9001:2015 and ISO 14001:2015 certifications and over a decade of export experience, Anebon delivers the high precision and consistency that OEMs across aerospace, medical, automotive, electronics, and robotics demand.

Send your 2D drawings and 3D models for a fast DFM review and quotation-typical response times are within 24–48 hours on working days. Whether you need a handful of rapid prototypes or long-term production of welded custom sheet metal assemblies, Anebon’s integrated capabilities help you move from concept to qualified parts with fewer handoffs and better results.