Projection Welding

Projection welding is a resistance welding process that uses raised sections (projections) on one or both workpieces to localize the welding current and force. This technique excels at attaching fasteners, creating multiple simultaneous welds, and joining dissimilar thickness materials with precision and speed.

How Projection Welding Works

Projection welding uses embossed or machined projections on one workpiece to concentrate the welding current at specific points. When current flows through these projections, they rapidly heat up and collapse under electrode pressure, forming solid welds.

The projections serve to localize heat generation and control weld location precisely. Multiple projections can be used to create several welds in a single operation, significantly increasing production efficiency.

Types of Projections

•
Embossed Projections
Stamped dimples in sheet metal for sheet-to-sheet joining
•
Solid Projections
Machined or forged projections on fasteners and thick parts
•
Annular Projections
Ring-shaped projections for hermetic seals and studs

Key Parameters

Weld Current

8,000 - 40,000 A

Weld Time

0.05 - 0.5 sec

Electrode Force

2 - 20 kN

Projection Height

0.5 - 3 mm

Advantages of Projection Welding

Projection welding offers unique benefits for high-volume fastener and assembly applications.

Multiple Welds

Create multiple welds simultaneously using multiple projections in a single operation.

Thick to Thin

Effectively join thick to thin materials where spot welding would be difficult.

Precise Location

Projections ensure accurate weld placement for consistent part-to-part quality.

Higher Strength

Concentrated current flow through projections creates stronger individual welds.

Less Marking

Minimal surface marking on the non-projection side of the workpiece.

Fast Cycle Times

High-speed production with typical cycle times under one second.

Applications

Projection welding is particularly suited for attaching fasteners and creating precise, repeatable assemblies.

•Weld nuts and bolts
•Captive fasteners
•Brackets and clips
•Cross-wire welding
•Sheet metal assemblies
•Automotive components
•Electrical contacts
•Metal furniture hardware

Industries

High-volume manufacturing industries rely on projection welding for efficient fastener attachment and assembly.

Automotive

Electronics

Appliances

Furniture

Fastener Mfg

Metal Fabrication

Projection vs Spot Welding