On Sat, 18 Jun 2011 07:48:59 -0400, "Tom Gardner"
wrote:

I have a new a product that will use two pieces, 4" long of 1/4-20 threaded
rod. Each piece will need to have two 20 degree bends, each bend will be
1-1/2" from each end and on the same plane. A Nylon insert locknut will
thread on each end about 1/2" to hold three pieces sandwiched together.
This is an angled variation on a standard product that uses two 1/4" x 4"
carriage bolts in a straight configuration.

I have to figure out how to bend the rod to the correct angle and on the
same plane without cracking the rod or boogering the threads where the nuts
go. The application doesn't require extreme strength, the cheapest
allthread is plenty strong if it isn't cracked.

The requirement is for 1k pieces per day at a total cost of =$.20 each

The problems I see are that the saw cut pieces have to be deburred to get a
nut started and if I bend the parts in a form on a punch press, I'd be
worried about smearing the threads and any secondary operation might push
the cost window. Ideally, I imagine a die that parts the rod and bends it
in one hit with a spring-loaded feeder that the operator drops in a standard
36" length of allthread every nine hits.


I'd put a couple of the suggestions above together.

Make 4" rods on a screw machine or CNC lathe with just the ends
threaded. Could do this yourself or farm it out. This would bend way
better than all thread and should be cheaper in manufacturing
quantities.

Bend a whole bunch at a time in a form die.

My advice is worth what you paid for it.

Karl