Thickness before and after forming
Thickness before and after forming
(OP)
Hi all,
Does exists any table, papers, tips of fabrication or suggestion in any norm (ASME VIII D1 or another) that says about of difference between thickness before and after forming?, for example 10%, 15%, 20% plus than design thickness, my question is about formed heads.
Cheers
D.Marshall





RE: Thickness before and after forming
Regards.
RE: Thickness before and after forming
RE: Thickness before and after forming
Thinning is minimal when shells are rolled. Heads are a different story. How much they thin depends on the forming method, shape, starting thickness, size and material properties. There is not table or published rule of thumb. Contact the manufacturer.
RE: Thickness before and after forming
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Thickness before and after forming
I just wanted to know a little about how much thickness more is relatively common in the industry (order of magnitude). I see in the StMan link's says a guy "1/16" for head thicknesses 1/2" thick and under and 15% for head thicknesses above 1/2"", this is OK for me, since it is only for general culture not for to design, however the most important of their comments is to contact the supplier and it is his job to accomplish my nominal thickness after forming.
Thanks again..
D.Marshall
RE: Thickness before and after forming
So, if YOU have questions, go measure it after forming. Reject ALL heads not meeting your minimum thickness . Don't try to guess what will be required as they roll and distort the head during forming. And, truthfully, you really don't care what the rest of the thicknesses of the head were before forming. Unless a rocket or missile pressure vessel when final vessel weight is a critical requirement.