Permissible Stresses:

The subsequent are the permissible stresses and design guidelines for fillet welds:

While the welded joints are constructed of mild steel (conforming to IS 226: 1975) as the parent metal and electrodes (conforming to IS 814: 1979), the allowable stresses (Table) will be as for parent metal (Fe 250).

(b) The combined stress within fillet welds shall be limited through

where, f_e = equivalent combined stress,

f = axial stress,

fbt , fbc = normal stress in tension/compression due to bending forces, and

q = shear stress.

Therefore, f_e should not exceed the value 110 N/mm².

(i)  A single fillet weld shall not be subjected to bending.

(ii) The load carrying capacity of a fillet weld = f_e Σ A.L.

(iii) For site welds this might be reduced by 20%.

(iv) If winds or earthquake stresses are involved, the above stresses may be increased by 25%.