Technical How much wheel stud into lug nut?

The juice brakes on the front of my 36 are from 42-48 ford and the wheel studs are not very long, maybe 3/4" long at the most. When I mock up my wheels I might be getting 1/2" of thread into the wheel lug. Is that enough? Never really was too concerned on other cars I own but these studs just seem so short (to me) maybe I am concerned about nothing, what does the HAMB say? Red straw shows how much stud protrudes from the cone of the wheel.

Also, IF I do need longer studs as shown below, I assume this style just presses in like normal studs and does NOT need to be drilled out as some of the other fearly ord studs do? PLMK, thanks!

 

What do the inside of your lugnuts look like?
Sometimes the thread is recessed, so I guess my question really is, how many threads are actually holding to the lugnut?

 

To get the most hold a stud or bold needs to go all the way thru the nut. Most race specs want the threads thru the nut equal to the diameter of the stud. Some want more.

 

Not nearly enough engagement.
When torquing the lugs you will bend and distort the threads.
When you realize the actual thread depth and width of each thread it will alarm you to find exactly what’s holding your wheel in place.
You need full lug nut engagement. This is one area to not cut corners.

 

The min length is the diameter of the bolt,
from Google:
Caution: It appears that one could theoretically increase the thread strength by increasing the length of engagement. However, as illustrated in the Load Distribution chart above, the first thread will be taking the majority of the applied load. For carbon steel fasteners (including tapped holes) the length of engagement would be limited to approximately one nominal diameter (approximately 1-1/2 times the diameter for aluminum). After that, there is no appreciable increase in strength. Once the applied load has exceeded the first thread's capacity, it will fail and subsequently cause the remaining threads to fail in succession.

 

Looks to me like you have 1/2" engagement on a 7/8" stud (but not all of that is threaded. You'd maybe get a touch more engagement with ET (extended taper) nuts, but you need to ensure they don't bottom out on the drum instead of clamping the wheel. What diameter size holes are in the wheels?

A couple of years ago I purchased a car fitted with 5 spoke Americans, and the previous owner had used tapered nuts. I near shit my pants when I found literally no more than 3 turns on each. ET type fixed that.

Chris

 

If you go and replace those studs you will find they are swedged into the face of the hub. Need to cut the swedge before pressing out.

 

The stud should protrude past the end of the lug nut at least 1.5 threads. For an enclosed lug nut like an acorn it should almost bottom out.

On a side note these lug nuts make break where the arrow is pointing.

 

Yes, they are swedged. However cutting the swedge is not easy. I pressed them out 'as is' and the swedge just deforms as it passes through the hub flange. But, it is IMPERATIVE that the back side of the flange is supported on the press bed. A suitable sized deep well impact socket or section of heavy wall tube/pipe will suffice, but DO NOT press against an unsupported hub/drum/flange/lug bolt.

Ray

 

^^^ yup. Most parts stores can do them correctly for a nominal fee.

 

Thanks for all of the info, below are the rocket racing "bullit" lug nuts, they are threaded pretty much all the way to the tip, as you can see I checked with the red straw and have about 1/2" of thread going into the lug, the studs are 1/2".... also best I can tell I can get about 6 full revolutions by hand and maybe 1-2 more with my wrench. I put them on just to mock up the wheels and see how the car would look. See below.

Pleased with the way these look just very concerned about the lug situation. In fact, so much so, that I am considering buying replacement 1pc hubs and the drums to fit, they will come with new, hopefully longer studs. If memory serves speedway sells some to replace these 12" one piece 42-48 fomoco items, can anyone confirm?

 

The wheels look great! Do not be afraid to replace the lug studs with suitable longer studs and use the drums/hubs you have now, assuming they are otherwise serviceable. I have done a set of late '40s drums that way but, unfortunately, do not remember the Dorman products part number for the studs I used. I no longer have that car, so I can't look to see what they were......but they ARE available in the catalog.

Ray

 

Nobody makes a drum and hub in one piece for these old Fords. Look at the pics and descriptions close to understand before you buy.

 

as Hnstray said take them into a auto parts place that can change or do it yourself as he described.a store with an assortment of studs can easily match the shank if you do it yourself take one in.wheels look good

 

Kudos to Happydaze!

Well good news, for $11.99 I solved my issues with a set of ET lugs as Chris suggested above, Thanks Chris
I did confirm the ET lugs do not protrude out further than the hub as shown below, so now I have more than 10 full rotations on actual threads, little bummed that I could not use my bullit lugs but so be it, better safe than sorry.

 

I know some applications don't need as much holding power, but a good rule is 1 1/2 time the diameter and you can not go wrong. 1/2" diameter stud / bolt should thread into the nut or part 3/4".