Permissible Stresses:

(a) For full stress, butt welds must be reinforced with excess weld metal and sealed as shown in Figure 19(a). When sealing run is not possible the effective throat thickness is reduced by the multiplying factor 5/8 of the thickness of the thinner plate.

(b) In butt weld throat, the stresses in tension, compression or shear shall not exceed those specified for the parent metal. For site welds this may be reduced by 20%.

(c) Combined stress within butt welds shall not exceed the permissible stresses in the parent metal nor the following:

For bending and shear,

For bending, bearing and shear,

(The symbols have the same meaning as in Eq.

(i) the Intermittent welds should resist shear only.

(ii) The load carrying capacity of butt welds, P = fe .Σ A.l.