rethreading a 5/8-18 bolt to 5/8-11

[littleboss]

I have a brass stud on the tripod of a transit that has 5/8-18 threads. The adapter I need to thread onto it has 5/8-11. Is there enough thread there for me to rethread it to 5/8-11? It doesn't have to hold much other than the transit mounted on the adapter.

Thanks

 

[ez-duzit]

You should be able to locate the proper adapter.

 

[littleboss]

Can't find one. This is what I have but it's 5/8-11 because that's the normal thread pitch. My tripod is probably 60 years old
https://surveyingsupplies.com/seco-tripod-adapter-5-8-x-11-to-3-1-2-x-8-2130-00/?gclid=Cj0KCQjwpNr4BRDYARIsAADIx9xePh4ZhUUTOT8cdD86uA0fg1vDQfayfW2SdsMm0xT-Wf5MRQg0B6caAvcwEALw_wcB

 

[ez-duzit]

Can't find one...

Try harder.

 

[seber]

bore it out and tap for a Keensert.

 

[Gotcha640]

Depending on level of precision needed, get someone to weld a bolt to a nut, or machine a piece with the male and female as needed?

Can the stud be replaced without destroying the tripod? Can the threaded insert in the instrument be replaced?

 

[littleboss]

Try harder.

As I said as far as I can tell they don't make one. Why don't you show me one or do you just like to up your post count and waste peoples time?

 

[littleboss]

Depending on level of precision needed, get someone to weld a bolt to a nut, or machine a piece with the male and female as needed?

Can the stud be replaced without destroying the tripod? Can the threaded insert in the instrument be replaced?

The tripod is an antique and worth quite a bit so I don't want to modify it in any way.

 

[ez-duzit]

Unsubscribed.

 

[Gotcha640]

The tripod is an antique and worth quite a bit so I don't want to modify it in any way.

What about the bolt and the nut? Nut to fit tripod, bolt to fit instrument, weld, grind/finish as needed, profit?

 

[M6erfan]

Something like a puller adapter might work, not sure. Worth a look at mcmaster or Grainger online catalogs

 

[dontlifttoshift]

https://www.grainger.com/product/OTC-Threaded-Adapter-3GZN2

 

[Gotcha640]

I missed that you already have an adapter, looking at pics it appears some types could take a helicoil. The one posted above appears solid metal, is yours like that?

Kits are about $40 with tap, drill bit, inserts. You might get away with clamping it to a bench and a hand drill, and vise grips to turn the tap, drill press and tap handle would be better. If you aren't confident cutting threads, it might be worth paying a shop to do it so you don't have to buy the tools. I can't imagine more than $100, probably a lot less depending on where in the world you live.

Running the die over the stud on the tripod doesn't sound like a good idea to me.

Just running the fine thread tap down the adapter also doesn't sound great.

I have worked in a machine shop, and cobbled together a lot of parts on a 69 beetle, with varying amounts of jb weld, but threaded insert is the right way to rethread a hole around the same size.

 

[engineer2]

McMaster Carr
https://www.mcmaster.com/couplings/...emale-hex-thread-adapters/thread-size~5-8-11/

 

[littleboss]

https://www.grainger.com/product/OTC-Threaded-Adapter-3GZN2

Thanks. That would work it would just stick up quite a bit. I prefer the adapter to mount flush against the tripod

 

[littleboss]

I missed that you already have an adapter, looking at pics it appears some types could take a helicoil. The one posted above appears solid metal, is yours like that?

Kits are about $40 with tap, drill bit, inserts. You might get away with clamping it to a bench and a hand drill, and vise grips to turn the tap, drill press and tap handle would be better. If you aren't confident cutting threads, it might be worth paying a shop to do it so you don't have to buy the tools. I can't imagine more than $100, probably a lot less depending on where in the world you live.

Running the die over the stud on the tripod doesn't sound like a good idea to me.

Just running the fine thread tap down the adapter also doesn't sound great.

I have worked in a machine shop, and cobbled together a lot of parts on a 69 beetle, with varying amounts of jb weld, but threaded insert is the right way to rethread a hole around the same size.

The adapter is aluminum and fairly thin where the threads are. Only about 2 or three threads there. I have a drill press so that's not a problem. As thin as the aluminum is looks like most of the helicoil would be sticking out. I guess I could cut it off or let part of it stick up into the "bowl" portion of the adapter.

Maybe I should just drill out the hole on the adapter, slide it down over the brass stud and put some JB weld on top? I could get it off that way and not harm the brass. JB weld should be plenty strong to hold that adapter and tripod. I could even use the weaker JB quick weld stuff. Thoughts?

 

[engineer2]

Pictures would help.
I looked at photographic equipment and they seem to use 5/8-11 and 5/8-27, but not 5/8-18.
5/8-18 is a flare fitting thread size.
1/2-20 to 5/8-18 is a Hole Saw Arbor Adaptor size
Maybe you can make your own out of brass?

 

[Gotcha640]

Jb weld the adapter to the brass stud? Not sure how that would help, and you said you don't want to permanently alter the tripod. Maybe I misunderstood.

I think helicoiling the adapter would be reasonable, cut off the excess threads, but I recognize you're doubling the price of the adapter. No idea if that's worth doing.

Since it's not structural, maybe you could just smoosh some jb weld in and tap that.

 

[littleboss]

Jb weld the adapter to the brass stud? Not sure how that would help, and you said you don't want to permanently alter the tripod. Maybe I misunderstood.

I think helicoiling the adapter would be reasonable, cut off the excess threads, but I recognize you're doubling the price of the adapter. No idea if that's worth doing.

Since it's not structural, maybe you could just smoosh some jb weld in and tap that.

I was thinking just drill the hole on the adapter out, then sit it down over the brass stud. A little JB weld on top and on the adapter should hold it in place.
As you said I could also try tapping JB weld

 

[littleboss]

Pictures would help.
I looked at photographic equipment and they seem to use 5/8-11 and 5/8-27, but not 5/8-18.
5/8-18 is a flare fitting thread size.
1/2-20 to 5/8-18 is a Hole Saw Arbor Adaptor size
Maybe you can make your own out of brass?

You can see the adapter I bought in the link a few posts above. The tripod is non standard threads of 5/8-18 fine thread whereas all newer tripods are 5/8 11 coarse thread

Tripod is a K&E designated for a plane table.. Looks like this one

https://www.ebay.com/itm/K-E-Keuffel-Esser-Alidade-w-Plane-Table-Tripod-Vintage-Surveying-/184168253026

see if you can view the pix here

https://www.amazon.com/photos/shared/ghb8UkPTSSO10ajs4SkO_g.9XK6Zf2FBx1KKHuzTYM1QS

 

[matt_i]

Thanks. That would work it would just stick up quite a bit. I prefer the adapter to mount flush against the tripod

If this is just temporary/quickie I'd use a block of wood to make up the difference in the flanges. Glue-up a block to get the right height.

More complex would be an aluminum tube spacer/bore a hole in solid-round.

 

[littleboss]

If this is just temporary/quickie I'd use a block of wood to make up the difference in the flanges. Glue-up a block to get the right height.

More complex would be an aluminum tube spacer/bore a hole in solid-round.

A transit is going to set on it permanently and it will be sitting in my Great Room so it needs to look good . I have a place in Colorado and a friend of mine wrote a computer program that lets me identify all of the mountains using coordinates.

 

[RTM]

I would think an attractive piece of wood of the appropriate diameter to match your Seco, new female thread on the top, and a stud sticking out the bottom to match the Seco.

What is the 3-1/2” -8 thread for?

 

[littleboss]

I would think an attractive piece of wood of the appropriate diameter to match your Seco, new female thread on the top, and a stud sticking out the bottom to match the Seco.

What is the 3-1/2” -8 thread for?

The transit mounts to that thread

 

[cherrybomb]

Go find an old wooden baseball bat.You can pick your diameter,length or what ever,taper your looking for.Thats your adapter base,you just have to figure how you want to join it,threaded,ream to fit,J.B.Weld.

 

[littleboss]

Go find an old wooden baseball bat.You can pick your diameter,length or what ever,taper your looking for.Thats your adapter base,you just have to figure how you want to join it,threaded,ream to fit,J.B.Weld.

I already have the aluminum base that fits the transit. I just need to attach it to the brass stud

 

[bob15]

Who makes the transit & tripod?

 

[Millwrong]

I'd be modifying the adapter instead of the antique tripod.



If you're capable, build up the inside of the threaded hole with a tig welder, and re-tap for 5/8" fine thread.


If you can't do that, just drill out the hole on the adapter to 11/16", and use a 5/8" washer and fine thread nut to secure it to the tripod.

 

[noid]

If it doesn't need to hold strongly, this is where 3D printing an adapter would shine.

As recently as yesterday I had to extended and adapt a stud from m5 odd ball thread ***** to M6 fine thread; worked perfectly.

 

[littleboss]

Who makes the transit & tripod?

K&E 74-0000 “Engineer’s transit”.


Tripod is a K&E designated for a plane table.. Looks like this one

https://www.ebay.com/itm/K-E-Keuffel...-/184168253026

 

[littleboss]

I'd be modifying the adapter instead of the antique tripod.



If you're capable, build up the inside of the threaded hole with a tig welder, and re-tap for 5/8" fine thread.


If you can't do that, just drill out the hole on the adapter to 11/16", and use a 5/8" washer and fine thread nut to secure it to the tripod.

I am not sure there is enough thread on the brass stud but will try that first. I sold my Tig to my nephew so would have to get him to do it...

 

[bob15]

Have you tried contacting anyone for an adapter?

Maybe: http://www.antiquesurveying.com/index.html

https://www.stakemill.com/index.php?main_page=index&cPath=371_372

https://www.engineersupply.com/surveying-equipment-adapters.aspx

 

[LeeG]

Heck, it shouldn’t be hard to machine a nice looking adapter from some brass bar stock. If you had something with the stud and recess next to each other rather than stacked, it would only add a little to the height

Edit:
Something like this maybe

View media item 105516