Fillet and Groove Welds in Structural Steel Field Welding

Groove weld vs. fillet weld

In steel erection, completing high-quality welds with as little rework as possible is a critical part of maximizing productivity, along with keeping projects on schedule and within budget.

On structural jobsites, though fillet and groove welds are both used, fillet welds are the most common. The strength required for the application typically determines when a more complicated complete joint penetration weld should be used instead of a fillet weld.

Here’s an overview of these two common types of welds on structural jobsites.

What is a fillet weld?

• The most common and easiest type to produce in structural steel field welding. 
• Often used in welded connections with T, lap and corner joint configurations, though it can be found throughout a project.
• Is generally visually inspected and rarely requires additional quality assurance testing.
• Widely used on jobsites, but typical applications using fillet welds include shear tabs, cover plates, bracing connections and column bases, as well as seam and stitch welds.

Welders can often complete these faster and do more of them compared to more difficult groove welds.

What is a groove weld?

• Can be partial joint penetration (PJP) or complete joint penetration (CJP) depending on the strength requirements.
• Makes up a much smaller percentage of the welds on projects.
• Often used for moment connections, column splices and connections at hollow structural steel (HSS) members.
• Takes more time to complete and requires highly skilled welders.
• Typically requires special beveling
• Requires additional testing and verification to ensure weld quality, especially for CJP groove welds.

Because groove welds take more time and skill to complete, they can be a source of bottlenecks on a structural jobsite. Often, more labor can be dedicated to fillet welds as needed, which may not be possible with groove welds if an operation doesn’t have as many highly skilled welders who can complete them.

Structural steel welding tips

Now that you’ve learned about the basic welds on a jobsite, learn how you can improve productivity on your more complicated welds. Read this article for more information about column splice and moment welded connections on structural steel projects.