Capacitor Discharge (CD) stud welding, using very short weld times,
permits the welding of small-diameter studs to thin, lightweight
materials. The weld cycle can be completed in 0.01 seconds on material
as thin as 0.020" (0.5mm). These fast weld times minimize heat
buildup, resulting in welds with very little distortion, discoloration,
or burning. Therefore, CD stud welding is often used when appearance
is a critical product feature.
CD stud welding uses a capacitor storage system to produce a rapid
electrical discharge, stud welding guns, and fasteners. No ferrules
or flux are needed. The CD stud welding method, used mainly for
welding mild steel, stainless steel, and aluminum studs, includes
two primary techniques: Contact and Gap. Both require a specially
designed stud with a projection, or ignition tip, on its weld end.
This tip provides accurate welding time control with precise repeatability.
CD stud welding creates high integrity welds even on thin gauge
materials. Additionally, it allows the welding of dissimilar metals
because the weld penetration is so slight that metallurgical problems
are prevented. The quality, productivity, and cost advantages of
CD stud welding include:
Improved Quality
Attractive appearance with minimal burn —
Often important in cosmetic applications, CD stud welding offers
appealing one-sided welds with no reverse-side dimples.
Strength in lightweight applications — On
very lightweight material that would be compromised when using other
fastening processes, CD stud welding creates a strong, high quality
bond.
Minimal backside marking — CD stud welding
allows backsides to be prepainted without damage to the paint.
Productivity
Fast process — With its extremely short
weld times, CD stud welding substantially increases productivity.
Fewer assembly steps — Like Arc stud welding,
CD stud welding eliminates punching, drilling, tapping, and riveting.
Economic Advantages
Labor savings — As in Arc stud welding,
the CD stud welding process saves significant costs by eliminating
through-hole preparation.
Fabrication savings — Often, an expensive,
oddly-shaped piece can be duplicated inexpensively by welding several
studs to a simple stock shape to form a metal fabrication.
