According to James H. :
Hi,

We're interested in producing (in relatively large numbers) 1/4-28 UNF 1/2"
Long screws with a quadruple-start. We're thinking of buying an older
(cam-type) screw machine to dedicate to this part. The question is, can
these cam-type machines (e.g. Acme-Gridley, Brown & Sharpe, etc.) cut screws
with multiple starts?

I believe that these machines don't have a thread-cutting
leadscrew and gearbox, so threads are most often cut with something like
a Geometric die head.

You'll have to get in touch with Geometric (or any of the other
people who make chasers for such die heads) to find out whether they can
make a special set of chasers to do this.

I suspect that they can -- and may provide the chasers for about
double the cost of standard chasers.

Good Luck,
DoN.

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