Concave contour weld symbol
A concave contour weld symbol is a graphical representation used to indicate the final weld face finish required for the weld joint after weld competition. A concave weld profile sinks in from its weld toe to weld center.
The symbol consists of a welding symbol for the weld joint type and a curved symbol above the main Basic weld symbol. The concave contour weld symbol is used to indicate a fillet weld or any other weld profile that has a concave contour.
Concave weld contour is not very common and mainly used for Fillet weld joints. Note that Concave contour weld symbol can also be used for groove, fillet, plug, slot, spot, projection, seam, stud, and edge welds.
AWS Contour Weld Symbols
In some cases, it is necessary to define the shape of a weld’s surface. For particular structures or mechanical parts, it is crucial to minimize stress concentrations. If mechanical techniques will be used to achieve the desired shape, additional shape symbols should be used along with the specified mechanical methods chosen to obtain that shape.
The needed weld contour can be achieved without using mechanical means. However, if such means are required to generate the necessary finish, the appropriate letter assigned to the following finishing methods must be added to the shape symbol.
- C – Chipping,
- G – Grinding,
- M – Machining,
- R – Rolling,
- H – Hammering
- U- Unspecified
- P =planishing
ISO 2553 Contour Weld Symbol
ISO 2553 is a standard that defines various symbols and conventions for representing different types of welds, including contour weld symbols. The weld symbol itself consists of a reference line, main weld symbol, supplementary concave weld symbol, an arrow, and a tail if required as shown in below example.