# Is It Possible To Put 9/16 Thread On A 5/8 Bolt?



## gubni (Nov 26, 2016)

I have some special wheel studs that are 5/18-18 thread. They do not make another stud that will work for my custom application, but the 5/8 thread is too big. I was wondering if it's possible to turn them down and put 9/16-18 thread on them? If so I have 32 that I need done. Below is the pic and I would need the threads to all the way to the splined part.


----------



## Terrywerm (Nov 26, 2016)

I don't see why not, as long as the studs are not hardened. Once they are turned down, the hardest part would be to get the thread cutting tool properly aligned with the existing threads. Once that is done, it would just be a matter of cutting the thread a little deeper as well as longer.

Personally, I think it would be much easier to modify the wheels a little bit to fit on the larger studs. Additionally, any studs that have to be replaced in the future would not need to be specially made for the application.


----------



## Billh50 (Nov 26, 2016)

You know Dorman makes 9/16 - 18 wheel studs


----------



## Terrywerm (Nov 26, 2016)

I thought 9/16"-18 studs were a standard size, but didn't remember for sure, and did not take the time to look it up. The only thing that might make a problem for the OP in that regard is that the knurled section might be smaller in diameter than the 5/8" studs.

Gubni, if you are trying to fit a set of wheels to a vehicle that they are not meant for, a set of adapter rings might be the better way to go.


----------



## tweinke (Nov 26, 2016)

Thinking wheel studs are pretty hard.


----------



## chips&more (Nov 26, 2016)

The 5/8” threads are probably rolled. And unless you can also roll the smaller threads that you what. You will not be able to duplicate the condition of the steel.


----------



## TOOLMASTER (Nov 26, 2016)

I would not want the liability


----------



## Chipper5783 (Nov 26, 2016)

You have not told us very much about the application.  Of course, the smaller stud is not going to be as strong, and you will lose the benefit of the rolled thread (assuming the existing ones are rolled).  Of course, for enough money, you could get them rolled, or set up and roll them yourself (which would be quite an undertaking).  Picking up an existing thread is not difficult.  The stud material is likely harder (tougher) than something like 1018, but it won't be too hard to cut threads in.  I have threaded induction hardened hydraulic shafting - it was hard on the tooling, but doable.  I suggest you get the proper form threading tools, then the root radius will be correct - giving you the most strength possible (short of rolling ).


----------



## gubni (Nov 27, 2016)

Thanks for the replies. The problem is I am using a special hub that needs a bigger knurl and this is the only dorman stud that will fit.

I have a hand tap and die set that includes 5/8. Is there a good way to take off the material other than a lathe?


----------



## rgray (Nov 27, 2016)

gubni said:


> Is there a good way to take off the material other than a lathe?



Grinder(surface) with a spin fixture. Whether using lathe or ginder, for that quantity it would be nice to have some kind of fixturing to make the job faster and repeatable. 
Building the fixturing would take as long as the job probably.

An old guy used to tell me: "someone somewhere already makes what you need". Finding it is the hard part.


----------



## Terrywerm (Nov 27, 2016)

Gubni, you mentioned earlier that you need 32 of them, which tells me that there are 8 per wheel, meaning that this is for a 3/4 or 1 ton truck. I also went back and read your introductory post where you indicated that you have a "rock bouncer" which I suspect is another name for a rock crawler. So, I am guessing that you are trying to fit steel disk wheels with oversize tires to your axles. Considering the severe duty that your wheels and lugs will endure, there is no way that I would do anything to weaken the studs in any way.  I personally would not want the liability.

We have nothing against helping you out a bit, but you need to tell us a little more about what you are trying to do. There are other members here that have experience with rock crawlers and other sorts of modified vehicles, and they may be able to help you out. As the old saying goes, there is more than one way to skin a cat. In the interest of helping you out, I have a few questions for you:

Have you considered modifying the holes in the wheels?  It may be much easier and a stronger solution as well.
Are the wheels hub piloted, or are they stud piloted?
What is the Dorman part number for the stud you are trying to use?
What year and make vehicle are the axles or hubs from?
I found 5/8" Dorman studs that are 2" in length with threads that go all the way up to the knurl. Take a look at this part number for starters:  610-048    It is meant to fit a 1972 Dodge 1 ton (D300)  It has a knurl diameter of .660" so will not fit a Ford hub unless you ream the holes in the hub slightly, but that might be a bit tricky to get the hole diameter just right. Even so, it would be easier and safer to modify the hubs or modify the wheels than to modify the wheel studs.

Share a little more information with us, we like a good challenge!


----------



## Tony Wells (Nov 28, 2016)

Even putting a new set of holes in the hub abandoning the old ones would be a safer thing to do. Recutting those threads without a relief groove would be absolutely necessary if you choose to go ahead with that approach, but there will likely be a flaw in the new threads where the old ones stopped. This would be a highly stressed point on the stud making them weaker than designed.


----------



## Dave Smith (Nov 28, 2016)

another possibility would be to get 32 good hardened 9/16 -18 bolts with enough threads and then make some bushings to fit them tight in the hub with no slop-----as long as you have enough space behind the hub for the heads they should work fine---then just check them often---You could go to finer thread on the bolts to match regular lug nuts------Dave


----------



## johnreese (Nov 29, 2016)

The original thread was a rolled thread .  Great for resisting fatigue.
If you turn down the bolt and cut a new thread you have stress concentrations at the root of the thread.  Poor fatigue life.
And then there are issues of liability.
Safer to modify the wheels.


----------



## TOOLMASTER (Nov 29, 2016)

how about drilling out the rims for a bigger nut?


----------



## Yumamechanic (Dec 20, 2016)

I would suggest that piloted drill bit followed by a reamer on the wheels would be the proper answer. As it would be safest option giving you full strength and would be 32 quick clean operations.

Sean


----------



## gubni (Dec 20, 2016)

The solution must be independent of the wheels. I decided to sleeve it and to use the OEM studs.


----------

