Static Strength
For full penetration butt welds made with a matching metal the strength is the same as the parent metal
- an allowable stress specification is used whether loading in tension, compression or shear
- the allowable stress is a fixed fraction of the shear yield strength of the metal
- typically for mild steel the allowable stress is 265MPa for butt welds and 215MPa for fillet welds (BS5950)
Partial penetration butt or fillet weld strengths are calculated on the size of the throat