Accurately bending threaded rod

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

Reply to
Tom Gardner
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Set up a grinder 4" before the saw so when the saw is through, the grinder has just removed the threads.

Set the distance so the saw cuts half-way through the ground section.

4" rod drops into female die, male bends it while the next one is cut.

One part every time the machine cycles.

Reply to
xpzzzz

How about bending solid rod, and then threading it.

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Reply to
Bob La Londe

Well how about starting with preformed 4" sections instead of using long pieces cut down?

I would contact a couple fastener companies and see what they have available. For the numbers you need I would think they might want to do business. I know you can buy all-thread at tractor supply as short as 8" with clean threads (not cut pieces).

Then it would be simple to make a die set for the press that an operator would lay 10 or so pieces in and hit the switch. repeat till order is done. With formed threads on each end no de-burr needed and no cutting in house.

Reply to
Steve W.

Could the form/die be relieved where the to-be-used threads are so there is no contact there? Bob

Reply to
Bob Engelhardt

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

Reply to
Karl Townsend

Can you build the machine around an induction heater so the bending wouldn't bugger the threads?

-- Happiness comes of the capacity to feel deeply, to enjoy simply, to think freely, to risk life, to be needed. -- Storm Jameson

Reply to
Larry Jaques

When you are talking a thousand a day, it probably makes more sense to have the rods made on a screw machine, and then bend the straight parts in a custom fixture. The screw machine cuts to length, threads the ends only and makes them burr-free.

Jon

Reply to
Jon Elson

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