How can I recut threads on a rod? The first set was not deep enough.

[ksp]

OK, I have cut 1/2" threads on a bunch of rods with my rigid pipe threader. Evidently something either moved or has wear because after threading them they are not quite right and the nut goes on very hard. I need to recut them. I can't run them through the rigid machine because there is a bent handle on the rod now. The question is, how can I recut the threads a little to clean them up? I have tried a die set with some success but it doesn't always work. Is there a special tool that will do this well? I must add that the threads are 6" deep. I have 200 of these to fix.
Thanks for any help.

 

[Dan Krager]

I can't run them through the rigid machine because there is a bent handle on the rod now.
Thanks for any help.

I can't get my head around the bent handle thing.
If it's what I suspect, then your only option is a thread chasing die, probably driven by hand. A ratchet die holder will help.
I have used a split die opened up for the first pass, then closed up for the second pass and the cut is clean and easy both times.
DanK

 

[mickri]

What type of treads are you cutting? Pipe threads are tapered. Can't even visualize 6" long pipe threads. Show us some pictures and we may be able to help you out.

With normal threads you pickup the thread to cut it a little deeper

 

[aliva]

Don't know if you have a lathe but if you do, single point them.

 

[mmcmdl]

A pic or 2 is worth 1000 words . If these could be mounted in your lathe ( if you have one ) , a geometric die head would clean them up but possibly take your major diameter undersize . It sounds like the rigid was not threading straight . More info and a few pics would help finding a solution .

 

[Jim F]

OK, I have cut 1/2" threads on a bunch of rods with my rigid pipe threader. Evidently something either moved or has wear because after threading them they are not quite right and the nut goes on very hard. I need to recut them. I can't run them through the rigid machine because there is a bent handle on the rod now. The question is, how can I recut the threads a little to clean them up? I have tried a die set with some success but it doesn't always work. Is there a special tool that will do this well? I must add that the threads are 6" deep. I have 200 of these to fix.
Thanks for any help.

There is your problem...........

 

[Firstram]

Pipe threaders also use dies for standard bolts, not just pipe.
Years ago we had a contract to make almost 200 3/4" anchor bolts for a local chemical company. They were adding a tank farm and we ended up getting the contract for the platforms, stairs, cable trays and pipe bridges as well. Unfortunately, we were expected to handle the installation on a cost plus basis.

When install time came, we quickly figured out the helper that threaded the bolts "forgot" to check every 3rd or 4th bolt for proper threads. He spent 2 1/2 days with a die nut chasing threads which now had concrete all over them!

 

[JimDawson]

I would use a hex die, a deep socket, an air impact wrench, and lots of cutting oil.

You may have to make the socket by welding a proper socket to a piece of pipe and weld another socket with the 1/2'' drive on the other end

VIKING High Speed Steel Hexagon Threading Dies

Long life cutting dieApplicationsUsed for threading rods, bolts, studs and other pieces requiring external threads.Outside hex configuration allows both wrench and dies stock use in threading.FeaturesSpecial Hi-Molybdenum tool steel, polished gold finish with black surface treated threads.

www.travers.com

 

[nnam]

With all good suggestions above, I would add one more for you to consider.

Depending on the tolerance, and how tight you're experiencing, you can try a wrapping them up with a sand paper/file and turns it a few times to see if it is good enough. That's very simple to do, so I would definitely do it first.

Another way, is if it is almost there, and you have a big enough sand blaster for it, try it. It may work, and work well.

 

[Just for fun]

I like Jim Dawson's idea. A picture sure would help.

Are they a one of thing? Can you recut 200 nuts to fit?