Anticlastic forming requires different sized mandrels depending on the
size of the item you’re making. Sinosoidal mandrels can be made from any
tapered steel bar. One that comes quickly to mind is the ring mandrel. Of
course, after you’ve put the fancy ripples in it, it won’t work too good
for rings (bg).
The only source of ‘drifts’ that I’m familiar with that would be large
enough to be made into a mandrels are those used by the steel workers
that put up the skeletons of the the typical NYC skyscrappers. Their tools
usually have a wrench on one end & the other end is tapered to aid in
lining up the holes in 2 pieces of steel.
FWIW. A ‘drift’ is any tapered tool used to line-up the holes in multiple
items, or seperated closely mated parts. They can very in size from a few
thousanths in. to several inches in diameter, lengths vary according to
diameter, 1 in to over 2 ft. The size is determined by the smallest
diameter hole the tool will go into.
The '97 MSC catalog lists 7 drift punches, 3/32" to 3/8" diameter, all 10
Probably the best stakes can be made from 1 to 1 1/2" diameter steel rod
about 18" long, that has been taper turned from full diameter to about
1/2". The small diameter depends on the size of the items to be formed
over it. Most any machine shop can handle taper turning on that scale.
I’ve made several tapered mandrels for forming chain rings.