Roymech Weld Stress table

[1980c3]

Do you guys know where the table here:

https://roymech.org/Useful_Tables/Form/Weld_strength.html

comes from? I haven't seen much allowance/calculation for butt/fillet welds in bending about its weak axis...

 

[MG1983]

at the link it says :
"The methods described below is based on the simple method of calculation of weld stress as identified in BS 5950- clause 6.7.8.2 . The other method identifed in BS 5950 - 1 clause 6.7.8.3 as the direction method uses the method of resolving the forces transmitted by unit thickness welds per unit length into traverse forces (FT ) and longitudinal forces (FL ). "