zeroUSA

Did you get any elongation before rupture?Was the machine properly calibrated?Perhaps your specimen had a crack in it. Mild steel should be ductile, but unless you have good source documentation you might have been sold a pig in a poke. What temperature was your test done at? Steel pressure vessels are not supposed to be hydrotested below 70 deg F due to concerns about brittle fracture. It's questionable if this rrestirction is really necessary with properly documented steels.