Joining

WSi supports several joining methods. All produce a Joining node in the Graph View.

Joining is an automatic workstep — it runs automatically when the geometry has been processed through cutting and bending steps. WSi creates the Joining node as part of the workflow when joining is applicable to the part geometry.

Available Joining Methods

• Arc welding (MIG/MAG) — most common; uses a continuous consumable wire electrode and shielding gas. Suitable for steel and non-ferrous metals.
• Resistance Spot Welding — applies pressure and current at discrete points. Fast and repeatable, no filler material. Common in high-volume production.
• TIG Welding — precise, high-quality welds with a non-consumable tungsten electrode. Slower than MIG/MAG.
• Brazing and Bonding — non-weld joining methods for specific material combinations.

See also: Threading and Finishing.

When to Use

Use arc welding (MIG/MAG) when:

• Continuous weld seams are required (fillet, butt, lap joints)
• Structural strength is needed across the full joint length
• Joining steel, stainless steel, or aluminium

Use Spot Welding when:

• Joining two or more sheet metal layers (typically 0.5–3 mm each)
• High production volume where speed is critical
• A discrete, accessible joint surface is available for electrodes
• No continuous seal weld is required

Use TIG Welding when:

• The joint requires the highest weld quality and precision
• Thin materials or cosmetic welds where appearance matters
• Working with stainless steel, aluminium, or exotic alloys

Choose TIG welding using the same steps as arc welding (MIG/MAG) below — select it as the joining method.

Step-by-step

WSi creates the Joining node automatically once the geometry has been processed through cutting and bending steps — there is nothing to click to trigger joining itself. Use these steps only when you need to choose or change the joining method for an existing Joining node:

1. Open the Graph View and locate the automatically created Joining node for the article.
2. Right-click the Joining node and select Edit process.
3. Choose the joining method you need — see Available Joining Methods above.
4. Confirm your choice. WSi updates the Joining node with the new method.

Result

After running any joining process:

• A Joining node appears in the Graph View, connected from the upstream cutting or bending nodes
• The Tree View shows each joining step with its geometry and any comments
• Export data includes the joining instructions for each step (coordinates for spot welding, weld path for arc welding)

Editing the Joining Sequence

After creating a Joining node, you can change the order of individual joining steps. Right-click the Joining node in the Graph View and select Edit joining sequence.

The sequence dialog shows all steps in order. To reorder:

• Select a step and click Move Up or Move Down to change its position
• The new order affects the export data sent to your CNC equipment

WSi computes an optimal sequence by default, but a different order may be needed for:

• Mechanical access — some joints are easier to reach before others are welded
• Thermal management — spreading heat-intensive steps apart prevents distortion
• Fixturing sequence — parts must be held in place before final welds

TIP

For automated CNC welding rigs, the sequence in WSi directly controls the robot program. Getting the order right in WSi means the robot program is correct without manual editing.

WARNING

Joining is an optional module. If the welding module is not licensed, the Joining workflow is blocked and you will see a licence notification. Contact your sales representative at WSoptics to obtain the welding licence.

Parameters

The parameters for this process are configured in the database — see the Processes page.

Technical Background

Joining unites separate metal pieces into a single assembly. The method selected depends on the materials involved, required joint strength, production volume, and visible quality standards.

Arc welding (MIG/MAG) is the most common welding process in sheet metal fabrication. A continuous wire electrode is fed through a welding torch while a shielding gas protects the molten weld pool from atmospheric contamination. MIG (Metal Inert Gas), typically using argon or helium, is used for non-ferrous metals such as aluminium and stainless steel. MAG (Metal Active Gas), typically using carbon dioxide, is used for carbon steel — the active gas participates in the arc chemistry and stabilizes the weld. The arc melts both the wire electrode and the base metal edges together, forming a fused joint as it cools.

Resistance spot welding clamps two or more overlapping sheet metal layers between two copper electrodes and passes a high electrical current through the stack. The electrical resistance at the metal-to-metal interface generates intense localized heat, melting and fusing the metals at a discrete point. The copper electrodes simultaneously cool the surrounding area, confining the weld zone. No filler material is used, making spot welding fast and economical for high-volume production of overlapping joints.

TIG welding uses a non-consumable tungsten electrode to produce the arc. Filler metal in the form of a separate rod is added manually by the operator. The tight arc control and slow, deliberate filler addition produce high-quality, precise welds. TIG is the process of choice for aerospace components, food-grade equipment, and any application where weld appearance and quality are critical.

Brazing joins metals using a filler alloy that melts above 450°C but below the melting point of the base metals. The base metals themselves do not melt — the filler is drawn into the joint gap by capillary action. Brazing produces smooth, uniform joints with minimal distortion and is commonly used for copper tubing, heat exchangers, and applications where a clean finish is important.

Adhesive bonding uses structural adhesives — typically epoxy or polyurethane-based — to bond large surface areas of metal. Adhesive bonds distribute stress more evenly across the joint compared to spot welds, improving fatigue performance. In many production environments, bonding is combined with spot welding (weld-bonding) to achieve both the strength of mechanical fastening and the sealing and stress-distribution benefits of adhesive bonding.