Most stud welding conversations start with the machine. The stud deserves just as much attention. Its thread, base, material and size decide what the finished part can hold and how the next assembly step goes together.
This guide covers the main types of weld studs, what each one is built for, and the details to confirm before ordering.
Start With What Attaches to the Stud
Before comparing stud welding studs, answer one practical question: what will connect to the stud once it is welded?
- A part clamped with a nut points to a threaded stud.
- A part fastened with a bolt or screw points to a tap pad.
- A clip, a hanger or a locating hole points to an unthreaded stud.
- Insulation points to insulation pins and anchors, a separate family of fasteners.
Threaded Studs
Threaded studs are the weld studs most people picture. The stud is welded to one side of the base metal, the mating part slides over it, and a nut clamps everything down. No hole goes through the base metal, so the face stays sealed. That advantage is covered in No More Holes: Why Stud Welding Is the Smarter Choice.
Davis Stud Welding stocks threaded studs for both stud welding processes:
- Threaded CD weld studs for thin sheet, in flanged, mini flanged and non flanged styles. Mild steel studs come copper plated as standard, and stainless steel and aluminum versions are also available. The flanged threaded CD weld stud in mild steel shows a typical imperial size range, and metric threaded CD weld studs cover common metric sizes.
- Threaded drawn arc studs for thicker material and heavier loads, such as the drawn arc threaded stud in mild steel.
When sizing a threaded stud, make sure the threaded length clears the mating part, any washer and the full height of the nut.
Unthreaded Studs
Unthreaded studs have no thread at all. They suit parts that only need to be located or held rather than clamped, such as locating pins, pivot points, hangers and anchors for push on clips or retainers.
Davis carries non threaded weld studs in mild steel, stainless steel and aluminum, in CD styles for sheet metal and drawn arc styles for heavier work.
Tap Pads (Internally Threaded Studs)
A tap pad turns the idea around. Instead of an external thread, it has a blind tapped hole. The mating part is fastened with a bolt or screw that threads into the pad.
Tap pads make sense when:
- the design calls for a bolt rather than a nut
- no stud end should stick out past the assembled part
- the part will be removed and refitted with standard bolts
Tap pads, including tapped arc fasteners with a reduced base in mild steel and stainless steel, are listed with the rest of the Davis weld studs.
Flanged, Mini Flanged or Non Flanged CD Studs
CD weld studs come in three base styles, and the choice affects both the weld and the fit.
| Base style | What it looks like | When it fits |
|---|---|---|
| Flanged | The weld end flares wider than the threaded shank | The usual starting point: the flange adds weld area and helps start the arc |
| Mini flanged | A smaller flange | Tighter layouts where strength needs are lower |
| Non flanged | The base matches the shank | When a nut must run down close to the base metal, or a flange would get in the way of the mating part |
Davis size charts list the flange diameter beside each thread size, which makes the styles easy to compare.
Stud manufacturers commonly recommend flanged studs where the design allows, since non flanged studs can give lower weld strength. Either way, the right style depends on the hole in the mating part, how close the nut needs to sit and the strength the joint needs. Test welds on the actual material confirm the choice, and tensile and torque testing shows how strong each weld really is.
Match the Stud Material to the Base Metal
As a starting rule, weld like to like: mild steel studs to mild steel, stainless studs to stainless and aluminum studs to aluminum. Aluminum brings its own challenges, covered in Why Aluminum Stud Welding Is Trickier Than You Think.
CD or Drawn Arc Studs?
Each weld stud is made for one process. CD weld studs have a small tip on the weld end that starts a very short arc, which keeps heat low on thin sheet. Drawn arc studs are built for a longer arc and are usually welded inside a ceramic ferrule, as explained in Understanding Ferrules.
For more on each process, see Capacitor Discharge Stud Welding: The Solution for Thin Metals and ARC Stud Welding: Engineering Strength into Every Connection.
What to Specify When Ordering Weld Studs
Weld stud sizes involve more than diameter. Have these details ready:
| Detail | Why it matters |
|---|---|
| Welding process | CD and drawn arc studs are not interchangeable |
| Thread size and pitch, or non threaded | Must match the nut, bolt or clip |
| Imperial or metric | Davis stocks both |
| Length | Drawn arc studs lose some length during welding, so confirm whether the drawing shows length before or after welding |
| Base style | Flanged, mini flanged or non flanged for CD studs |
| Stud material and plating | Should suit the base metal and the service environment |
| Base metal and thickness | Decides the process and the stud size the material can support |
Each Davis product page lists standard lengths, and larger sizes are available on request.
Weld Stud FAQ
What are threaded studs used for?
They fasten a part with a nut. The stud is welded to one side of the base metal, so no hole goes through it.
What is the difference between a threaded stud and a tap pad?
A threaded stud has an external thread for a nut. A tap pad has an internal thread for a bolt.
Are weld studs available in metric sizes?
Yes. Davis stocks metric threaded CD weld studs as well as imperial sizes.
Can any weld stud be used with any stud welder?
No. Each stud is made for CD or drawn arc welding and must match the equipment.
Why are some CD studs flanged?
The flange widens the weld end for a larger weld area and helps the arc start cleanly. Non flanged studs suit parts where a flange would get in the way.
Find the Right Weld Stud for the Job
Not sure which stud fits the part? The Davis Stud Welding team can help match the thread, base style, material and size to the application. Call 1 (855) 720-2977, contact the team or request a quote.