An additional thought unmentioned in this thread.
Rolling/Grain direction.
Omer Blodgett says...... (nobody knows better than this guy)
"Steel is not fully isotropic, and ductility is sensitive to rolling direction. When steel is strained parallel to the direction of rolling, the highest values of elongation are obtained. When it is stretched perpendicular to the rolling direction, ductility is reduced. The poorest ductility usually is measured in the through-thickness direction."
The full article and drawings are here
http://www.weldingmag.com/323/Issue/Article/False/13719/IssueI have this printed in color, laminated and posted
Just this summer I experienced the ugly side of this phenomina whilst doing some contract training at a local fabricator... The shop forman decided during the afternoon shift that he wanted to do bend tests the next morning and had somebody "prep" the coupons for me....... thanks alot!
Every weld broke, face, root all of em... I was beside myself. This was simple solid wire spray transfer on plain carbon and I monitored every pass. We did things over with properly prepped material and everybody qualified, but I'll tell you it is a terrible feeling watching one strap after another not even get to the bottom before it snapped!
This did nothing good to my already notable reputation as an autocratic control freak on the shop floor.