Thru-Decking Procedures for Structural Steel Welding

Drawn arc stud welding operations are used extensively in the construction industry. Not only do drawn arc studs function as fastening systems for sheet metal fabrication, construction equipment manufacturing, and structural steel manufacturing, they are also used to build large-scale infrastructure with composite building. With drawn arc shear connectors, bar anchors, and other studs, manufacturers can build composite materials. Stud welding offers a rapid, clean operation that results in a connection stronger than the stud or the welding surface. At Northland Fastening Systems, we provide a complete selection of drawn arc welding tools, studs, and accessories. We also provide repairs and service for most welding tool models, and our expert welding technicians can give guidance and advice on any project. If you’re working with drawn arc structural steel welding, NFS is your one-stop-shop for supplies.

Structural Steel Welding

One of the most important uses of drawn arc operations for structural steel welding is the thru-deck installation process. Weld thru-decking (studs abbreviated WTD) fastens decking material to steel beams. Building with decking welded to beams is a common construction practice, used to fabricate components in many types of buildings, from homes to skyscrapers.

In order to accurately attach studs through decking to the beam underneath, specific welding procedures should be followed.

Surface Preparation

Both the surface of your decking material and the steel beams should be properly prepared for a weld. This means removing any paint, rust, mill scale, dirt, moisture, and other contaminants. Galvanized surfaces on beams should have the galvanization removed at the weld point. Moisture from rain or humidity should be dried with a heat gun at the weld point. Additionally, if you are welding in cold weather, the weld point should be warmed to the touch but not overheated.


Finally, the decking and beam should be properly grounded to prevent loss of welding current. Using C-clamps or welding grounds attached to a beam flange where the surface has been ground to bare metal will prevent poor weld connections due to inadequate current.

Weld Specifications

Thru-deck welding requires currents typically between 1,500 to 1,900 amps. Your welding unit manual will specify the exact power source requirements determined by stud dimensions, decking thickness, and materials. Keep in mind that extensions of cables and changes to wire size can impact the current and compromise a weld. If you must run a long cable, you may need to run parallel cables to generate enough power for the weld site.


Thru-deck welding requires a special ceramic ferrule with wider gaps between teeth. These gaps allow for a hotter weld that can successfully fuse the stud through the decking to the steel beam. Most thru-decking welds will take between 0.8 to 1.6 seconds to fuse, and studs will plunge approximately 1/4″ to 1/2” depending on their length and decking thickness.

If you would like more information about drawn arc structural steel welding with thru-decking or need to order supplies, contact Northland Fastening Systems today at (651) 730-7770 or request a quote online.