What are weld studs?
Weld studs are unthreaded fasteners fused to steel with a stud welding gun and a ceramic ferrule, creating a full-strength bond in seconds without drilling or backside access.
Headed concrete weld studs vs shear connector studs
Headed concrete studs provide uplift and tension transfer into concrete. Shear connectors create composite action between steel beams and concrete slabs for shear transfer.
Weld stud sizes and lengths
Common construction sizes include 3/8", 1/2", 5/8", and larger for shear connectors, with lengths selected to achieve the specified embedment after deck thickness and fillet are considered.
Through-deck stud welding vs bare plate welding
Through-deck welding fuses studs through metal deck into the beam below using profile-matched ferrules. Bare plate welding places the stud directly on a flat steel surface.
Ferrule selection and purpose
Ferrules center the arc, contain molten metal, and form a uniform fillet. Always match the ferrule to the stud diameter (and deck profile for through-deck work).
Stud welding parameters overview
Proper welds depend on correct lift, time, and current for the stud diameter and base thickness. Use the gun manufacturer’s charts and verify with bend tests where required.
Weld stud spacing and edge distance basics
Observe plan requirements for minimum spacing, row offsets, and edge distances to ensure load transfer and avoid concrete breakout or localized plate distortion.
Inspection of welded studs
- Uniform 360° fillet with no undercut or gross porosity
- Stud perpendicular to the base
- Ferrule fully consumed and removed cleanly
- Bend or torque checks where specified
Applications for weld studs
- Composite beam construction with metal deck
- Anchoring plates and shapes before concrete placement
- Industrial platforms, equipment bases, bridge work
- Any rapid, permanent steel-to-steel or steel-to-concrete connection
Choosing weld stud diameter for your project
Select diameter by design load, base metal thickness, and specified spacing. Verify your power supply and gun can deliver required current for the chosen size.
Installation tools and setup
- Stud welding gun with correct chuck/ferrule grip
- Power source matched to stud diameter
- Ceramic ferrules for plate or through-deck
- Ground connection, PPE, and fume control
Common weld stud issues and quick fixes
- Lack of fillet: Increase time/current or check lift settings.
- Porosity/spatter: Replace damaged ferrules and dry consumables.
- Stud lean: Verify gun perpendicularity and ferrule seating.
Weld Studs FAQ
What sizes of weld studs are commonly used?
3/8", 1/2", and 5/8" are common for headed studs in building work, with larger diameters often specified for shear connectors. Always follow the sizes in your plans.
Do I need a ferrule for every weld?
Yes. Ferrules center the arc, contain molten metal, and shape the fillet. Use the ferrule that matches your stud diameter and, for through-deck, your deck profile.
Can I weld studs to galvanized steel?
Studs can be welded to galvanized steel when procedures address coating burn-off, ventilation, and post-weld protection per the project WPS.
How are shear connectors used in composite beams?
They are welded to the beam flange so the concrete slab and steel act together, improving stiffness and shear transfer.
How do I verify a good stud weld?
Look for a full, even fillet around the base and a plumb stud; perform bend tests or other inspections as specified.