Convex contour
An arc bulging away from the weld symbol: the face of the weld is to be convex.
How to read it
Contour symbols show how the face of a weld is to be formed. They sit on the same side of the reference line as the weld symbol they go with. A finish symbol can be added as well: its letter gives the method of finishing, not the degree, such as C for chipping, M for machining and G for grinding.
A fillet weld that is to be mechanically finished to a convex contour is shown with both the convex contour symbol and a finish symbol. The international standard has a convex symbol too, listed in India's IS 813:1986, which draws on ISO 2553.
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 symbolsConcave contourAn arc curving in toward the weld symbol: the face of the weld is to be concave.
- The same shape in African flagsFlag of the ComorosThe Comoros flag is four horizontal stripes, yellow, white, red and blue from the top, with a green triangle along the pole holding a white crescent and four white stars in a line between its tips. Norway’s Store norske leksikon explains the crescent as the symbol of Islam and the four stars as the four islands of the Comoros; Lex says the four stripes are said to stand for the islands too.
More welding symbols
The same shape elsewhere
Browse symbols drawn with arrows, curves and waves, lines or triangles.
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), Chapter 11, section II
- Scheme of symbols for welding, IS 813:1986, Bureau of Indian Standards (Internet Archive, Public.Resource.Org), Table 2
Researched, edited and approved by Rory Hansen before publishing. Last reviewed September 25, 2026. How we research
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