The selection of welding electrode caps directly affects welding quality, equipment efficiency and production costs. This ultimate guide is based on material science, process parameters and industry practice, to build a multi-dimensional selection decision-making system:
How to Selection the most suitable Cassette Type Single Facer Machine?
In the previous article, we talked about the relationship between the shape of the electrode cap and its use, and today's article is about how toSelection the most suitable electrode caps ultimate guide?
First, understand the core role of the electrode cap
The electrode cap assumes three core functions in spot welding:
Current Conduction: Concentrates thousands of amperes of welding current to the surface of the workpiece.
Pressure transfer: withstand 200-1000N welding pressure, to ensure that the workpiece close contact.
Heat dissipation management: Quickly dissipates the Joule heat generated during the welding process (temperatures up to 600-1000°C).
Typical consequences of selection errors:
Sticking of the zinc layer during welding of galvanised sheet metal (material mismatch)
Rapid electrode wear during welding of aluminium alloys (insufficient heat dissipation)
Burn-through in thin plate welding (wrong electrode shape)
Second, Core dimensions of electrode cap selection
1. Material selection: balance of conductivity, hardness and high temperature resistance
Three core indicators of electrode cap materials:
Conductivity (% IACS): affects the current transfer efficiency (copper standard conductivity 100% IACS)
Hardness (HRB): determines resistance to deformation
Softening temperature: ability to maintain strength at high temperatures
Comparison table of commonly used materials:
|
Material |
Conductivity (% IACS) |
Hardness (HRB) |
Softening temperature (°C) |
Typical application scenarios |
|
Chromium zirconium copper |
80-85 |
70-80 |
≥500 |
Mild steel, stainless steel continuous welding |
|
Beryllium copper |
45-50 |
100-120 |
≥300 |
Galvanised plate, high hardness plate |
|
Tungsten copper |
50-60 |
80-90 |
≥1000 |
Aluminium alloy, copper alloy welding |
|
Diffuse copper |
85-90 |
85-95 |
≥550 |
Coated plate, high temperature alloys |
Principle of material selection:
When welding highly conductive materials (e.g. copper), preference is given to chrome zirconium copper or dispersible copper
Beryllium copper is required for welding galvanised sheets (high hardness, reduces zinc layer sticking)
Tungsten copper for aluminium alloy welding (high temperature resistance and anti-adhesion)
2. Shape design: precise control of current density and contact area
Tapered electrode
End angle 60°-120°, large contact area
Application: Welding of medium-thick steel plates (1-3 mm), automotive bodywork components.
Spherical electrode
Radius of curvature of the end face R=25-100mm
Application: welding of thin plates (<1mm), electronic component joints
Flat electrodes
Used in conjunction with positioning jigs
Application: welding of shaped workpieces, multilayer boards
Customised shaped electrodes
Special structures such as tabs and grooves on the end surface
Application: sandwich structure (e.g. battery lug welding)
3. Dimensional matching: scientific calculation of diameter and radius of curvature. 4. Cooling system design: the key to preventing thermal failure.
After doing a lot of understanding in the front, the most important thing is testing. If you are in need of electrode caps now, you can contact us for free samples for testing.