Residual stress in parts can cause them to warp even while sitting. Rolled screws would surely have residual stress potential.
We ground some special welded billet cams. Straight as an arrow when we shipped them - warped nearly 0.012" TIR while shipping. The grinding reduced residual stress generated while welding and, whah-lah, pretzels.
From my experiences of late, this would not be surprising in a rolled thread part that wasn't properly stress relieved after processing.
A person adept at shaft straightening could either cold or hot straighten them. Better yet, take them back and let someone else deal with it.
A press can straighten them with care. You could even load down the ends and pry up in the middle with a 2x4 and straighten them adequately for use - again with care. |