Thanks for the feedback.
I checked thru the units again and yes if i use W = n/mm then units cancel out to mm. I had checked this but obviously, not very well. Makes it simple now if you have the load, just use Newtons and don't multiply by b.
Only need to multiply by B if your load is N/mm...
I was looking on the net using the search words listed in the subject line.
This eng tips forum came up, so I had a look.
MrMikee posted 23 June 06 16:29 with a formula from Blodgett "design of welded structures".
From Blodgett "Design of Welded Structures" Case 3c for beam supported at both...