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Help me design a threaded shaft "wrench"

rmcphearson

Hot Rolled
Joined
Jan 12, 2008
Location
Rochester, NY
This shaft has a 5/8-18 OD threaded end and a 3/8-24 internal thread. Both are RH threads. The other end of the shaft is the same. I need to make a tool that will prevent the shaft from turning CW as we are looking at it. The primary reason I need to prevent it from turning CW is so I can remove the RH bolt that is threaded into the other end of the shaft.

I'm thinking the best option is to get a 5/8-18 coupling nut and slice one end about an inch or so and screw it on and clamp it on the threads with something like this punch holder
punch holder - Yahoo Image Search Results

I need to use this tool over and over again. I want it took look professional. Is there anything off the shelf I could use? I couldn't find a stud remover this size. I don't think two jam nuts are going to work well.

Thanks,
Roland
 

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AFAIK that's about your only option and the one I would go for, ...personally I'd home brew then I know what quality of materials go in to it, …...I'd also make the clamping bolt separate from the handle.
 
I would use a coupling (or make your own) and split it on 1 side only.
I would plan to clamp the split sleeve together with a toggle/ cam or a clamp screw, and have a handle welded to the opposite side of the split.
(Think split boring bar sleeve, with a clamp mechanism similar to a bicycle seat clamp)
Here is a crude example, without a handle.
Split Couplings for Threaded Rigid Conduit • IMC Malleable Iron | Konkore Fittings

Voila'

Or just buy one of these:
Threaded Rod Wrenches – MCC Professional Tools
 
You could use one jam nut on a 3/8" bolt, on whichever bolt comes out first: take out the first bolt, screw on the jam nut, screw it back in, jam it, then remove the other bolt.

If the bolt never needs to come out of one end, you might loctite a setscrew in that end, then hold by means of an allen key. Or you might loctite a setscrew way down in the bottom of the hole permanently, then use a shorter bolt above it. Remove the bolt, then stick the allen key down the hole to hold it. Do on both ends. Loctite may not hold if the bolt is super tight. But then you should use an impact wrench to loosen the bolt, as then it probably won't break the loctite joint.
 
Get a 5/8-18 nut. Split one side with a hacksaw. Put it on the shaft and grab it with vise grip pliers.
 
Quick and dirty: Hard wood vise jaws. Make them thick. Clamp down on a solid 5/8-18 thread to form them to the thread shape. Then go to town on your hollow rod. This is probably better as a bench vise will hold the rod still while you are removing that bolt.

More professional(?): Get that coupling bolt but cut it completely in half. Weld the halves to a pair of channel lock pliers using a scrap of 5/8-18 thread for alignment. Done. By splitting it in half you will save time in use. You did say this is a repetitive job, didn't you.

But I like the wood vise jaws better. And yes, I have done that.

If you don't like the wood for the vise jaws, get a thick block of aluminum. Bore it through and tap it. You may have to counterbore one end due to the limited length of the tap. Cut it in two and them make the halves into vise jaws. It will probably last longer than wood.
 
More professional(?): Get that coupling bolt but cut it completely in half. Weld the halves to a pair of channel lock pliers using a scrap of 5/8-18 thread for alignment. Done. By splitting it in half you will save time in use. You did say this is a repetitive job, didn't you.

I like that :)
 
I take it the traditional thread wrench is not suitable as the rod end in question is not accessible for applying and removing the wrench as the rod is expected to be already attached or will be attached to something when the tool is applied.

You want this to look professional and be quick to use and it is also for sale or for personal use.?

In reality for personal use I would probably use the Vise Grip and welded split nut idea as it should work pretty well and is certainly cheap and easy..

If the item is for sale, what kind of price range are you thinking? I ask because i have a couple of somewhat "elegant' designs in mind but they won't be cheap to make. No sense spending time outlining what would be a non-starter due to cost issues.

Denis
 
I like that. I didn't think of it, but I wish I had.

I still like the vise idea better. It is going to be a bit awkward holding the pliers in one hand and removing the bolt with the other. The vise leaves two hands free.



Vise-Grip-type pliers might be handier than Channellock-type pump pliers.
 
This shaft has a 5/8-18 OD threaded end and a 3/8-24 internal thread. Both are RH threads. The other end of the shaft is the same. I need to make a tool that will prevent the shaft from turning CW as we are looking at it. The primary reason I need to prevent it from turning CW is so I can remove the RH bolt that is threaded into the other end of the shaft.

I'm thinking the best option is to get a 5/8-18 coupling nut and slice one end about an inch or so and screw it on and clamp it on the threads with something like this punch holder
punch holder - Yahoo Image Search Results

I need to use this tool over and over again. I want it took look professional. Is there anything off the shelf I could use? I couldn't find a stud remover this size. I don't think two jam nuts are going to work well.

Thanks,
Roland

Could you thread this to the 5/8” thread and maybe cut flats on the shaft end?
McMaster-Carr
 
Try a cordless impact wrench.

The 1/4” hex input will accept a hex to square drive adapter, then install a socket wrench, then give it a try.
 
My first thought was a pipe wrench but thats crude. I like the link (gbent) gave or the punch holding tool you gave a link to.
Or (epaIII's) vise grip suggestion. Vice grips with modified jaws are useful.
 
I think what I would do is buy a piece of Hex the same size as the 5/8-18 nut you want to use and thread it to make a hex bolt 3/8-24 thus making a 3/8" bolt with the same size hex as is screwed on the 5/8 part. Screw on the nut then screw in the 3/8" bolt into the 3/8" hole. Get just tight enough so that the flats match then use a deep socket and hold both hexes in one socket so neither will turn independently. Being that the threads are different it will not turn either way! You could also make both from the same piece of Hex.
 
I think what I would do is buy a piece of Hex the same size as the 5/8-18 nut you want to use and thread it to make a hex bolt 3/8-24 thus making a 3/8" bolt with the same size hex as is screwed on the 5/8 part. Screw on the nut then screw in the 3/8" bolt into the 3/8" hole. Get just tight enough so that the flats match then use a deep socket and hold both hexes in one socket so neither will turn independently. Being that the threads are different it will not turn either way! You could also make both from the same piece of Hex.

" Being that the threads are different it will not turn either way!"

Now that's the type of out the box thinking I like. You're hired! But it seems that might stress the shaft threads and require re-tapping. I already tried the 3/8fine-jam-nut-with-3/8fine-bolt idea that someone else mentioned and that didn't work well. I'm going to split a coupling nut as planned and either use the punch wrench as planned or vise grips.

Thanks all for the suggestions.
 
I think what I would do is buy a piece of Hex the same size as the 5/8-18 nut you want to use and thread it to make a hex bolt 3/8-24 thus making a 3/8" bolt with the same size hex as is screwed on the 5/8 part. Screw on the nut then screw in the 3/8" bolt into the 3/8" hole. Get just tight enough so that the flats match then use a deep socket and hold both hexes in one socket so neither will turn independently. Being that the threads are different it will not turn either way! You could also make both from the same piece of Hex.

You'll have to screw the outer nut on or off a few turns (perhaps) in order for the internal threads to get in phase with each other. It might work well, although I'm not sure it wouldn't be 'squishy' to tighten, and problematic to loosen off.
 
OP has a thread clamping solution, it should satisfy the requirements. He plans to use the tool many times. At some point the tool could slip on the threads and damage them.

I can't help but want to chase using differential pitch threads to solve this, because it is a cool property, and for other cases where clamping is not appropriate - like when the shaft is in a recess, or because the shaft is huge. That is Froneck's approach.

I already tried the 3/8fine-jam-nut-with-3/8fine-bolt idea that someone else mentioned and that didn't work well.

That is a different approach than what Froneck was suggesting.

Jam nuts do put a lot of force on just a few threads and can distort them. A longer nut helps. But also, the arrangement you described apparently had all the force going through that small 3/8" fastener as a torsional (twisting) load. That 3/8" fastener is strong in tension, but wimpy in twist compared to that 5/8" shaft.

Another approach.. What if you thread the 5/8 nut on the shaft, with a washer. Then bolt a heavy stop to the end of the shaft, 3/8" thick x 1" dia with a 3/8" hole, held on the end with a washer and a properly torqued 3/8" bolt? As the 5/8" nut engages the stop, the loading of the 3/8" bolt is purely in tension. Properly setup, it should not turn, or need only minimal help to hold. Remove 3/8" with impact.

I'm wondeirng how much torsional load Froneck's approach puts on the 3/8" fastener. Insignificant, I think. But I'm not sure how to estimate it.
 








 
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