The small arrows, triangles and flags on a fabrication drawing are welding symbols—a standardized shorthand that tells the welder what joint to make, how big, on which side, and where. Buyers do not need to master the whole system, but understanding the basics prevents the two expensive extremes: drawings that over-specify welding everywhere, and drawings that say nothing at all.
What does the basic weld symbol look like?
An arrow points at the joint; a reference line carries the instructions. A triangle on the line means a fillet weld—the workhorse of fabrication. Numbers give the weld size and length. Symbols below the line apply to the arrow side of the joint; symbols above apply to the other side.
What do the circle and the flag mean?
A circle where the arrow bends means weld all around the joint. A flag means a field weld—made at installation, not in the shop. Both matter to cost: all-around welds multiply weld inches, and field welds move work to the most expensive place to do it.
What happens when a drawing has no weld symbols?
The shop welds to its standard practice—which experienced fabricators size to the joint and the load. For routine work that is usually fine. For lifting components, structural connections and anything code-governed, explicit callouts and the applicable standard belong on the drawing.
Can you over-specify welding?
Easily—and it is one of the most common cost drivers we see. Calling out oversized fillets or continuous welds where intermittent would serve adds weld inches, labor hours and distortion without adding useful strength. Weld size should come from the load, not from habit or fear.
What should a buyer actually specify?
The requirement and the standard: what the part must carry, which code applies (AWS D1.1 for structural carbon, D1.6 for stainless), and any inspection level. A shop with certified welders—like our welding department—turns requirements into correct joints; that is the job.
Frequently asked questions
Not necessarily—stating the load and letting the shop size the welds works for routine parts. Symbols earn their place on structural and code work.
Shop welds are made under controlled conditions before delivery; field welds are made at installation. Shop welds are cheaper and easier to verify—good designs minimize field welding.
“Typical”—the same weld applies at all similar joints on the part. Convenient, but make sure “similar” is actually unambiguous.
Yes—we weld to the load and the application, and we ask when a joint deserves an explicit conversation.
Send the drawing, symbols or not
A & P Fabricating Solutions, LLC welds to AWS D1.1 and D1.6 with certified welders at our Appleton, Wisconsin shop. Send drawings to the quote request page—if a weld callout is going to cost you money without buying strength, we will flag it.
