"Bruce E Butts" wrote in message
...

Mike,
Veeduber recommends that one drill with a #40, deburr and then dimple with
the 1/8" dimple dies.

A 1/8" dimple die won't fit in a #40 hole, which is roughly 3/32.

I have done some like that and some using the #30 drill first. Sometimes
I have to 'open up' the hole a bit with a reamer when trying to put in the
rivet when I use the #40 bit first. Veeduber's advise was in reference to
using blind rivets iirc.

The springback dimple dies are meant for dimpling fuel tank skins so that
smearing sealant will not make the rivet stand proud of the dimple so I
think they may be a few thousandths oversize.

Most of the high quality dimple dies are of the springback configuration.
They are good for dimpling everything that needs to be dimpled, not just
tanks. They are not oversize. Some of the tool vendors sell special tank
dyes which produce a slightly deeper dimple, but that isn't a function of
whether they are springback dyes or not.


Hope this helps and remember all advice is worth what you paid for it!
Bruce

KB