Spot weld
A circle on the reference line: a spot weld, a resistance weld that joins sheets at a single point.
How to read it
Spot welding is a resistance welding process: the parts are held together under pressure between electrodes, and an electric current through them produces the heat that fuses them. The Navy's Steelworker course calls it probably the most commonly used type of resistance welding, and especially useful for sheet metal parts.
Resistance spot weld symbols have no arrow side or other side significance in themselves, which is why the symbol is centered on the reference line.
This explains what a symbol specifies on a drawing. It isn't welding instruction, and a drawing's own notes and the governing code take precedence.
Read next
- Next in Welding symbolsSeam weldA circle crossed by two lines on the reference line: a seam weld, a continuous weld made of overlapping spots.
- The same shape in BPMN symbolsSequence flow and message flowThe two arrows of BPMN. A solid arrow with a filled head is a sequence flow, the order of steps within one process; a dashed arrow that starts at a small open circle and ends in an open head is a message flow, a message passing between two participants.
More welding symbols
The same shape elsewhere
Browse symbols drawn with arrows, circles or lines.
Sources
- Steelworker, Volume 1, NAVEDTRA 14250, 1996, Naval Education and Training Professional Development and Technology Center, U.S. Navy (Internet Archive), Chapter 3, Drawings and specifications
- Welding Theory and Application, TM 9-237, 1967, Department of the Army (Internet Archive), Glossary; chapter 11, section II
- Scheme of symbols for welding, IS 813:1986, Bureau of Indian Standards (Internet Archive, Public.Resource.Org), Table 1
Researched, edited and approved by Rory Hansen before publishing. Last reviewed September 25, 2026. How we research
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