A useful source for diemaking

[Ballistics in Scotland]

173738

These are wheel studs with a 7/8-14 UNF thread for Volvo trucks, 97mm. in overall length although there are longer ones and other threads. As there would be hell and a half to pay if a truck's wheel falls off, they are probably better steel than many bolts and threaded rods. They are hardened, and so far I have annealed but not machined mine. A file test suggested that they would have been drillable with a carbide drill for sure, and perhaps HSS if a size suitable for the risk of bluntening was suitable. With bolts I have found that a drill slightly undersize, followed by the right one with the corners stoned rounded, gives a finish good enough for bullet sizing. Use of a special gunsmith's reamer would surely require annealing.

The authentic Volvo part may be expensive, but mine are pattern parts, and seem of good quality. They are made from individual forgings, with a forged-in 60 degree centre which isn't as accurate as one drilled on the lathe, but then neither is the loading press to ram alignment in many press and shellholder setups. At a pinch could be used to make your die with a drill press. Prices are still very variable, and at least in the UK this is one of the few things in which I have found eBay a long way from the best deal. It pays to shop around.

I don't believe any kind of loading die really requires the enlarged diameter above the 7/8in. threads, but it looks the part, and the diameter and fine splines give a good grip.

[EDG]

If you look closely at the threads of the Volvo studs you will see they roll formed instead of cut threads. The roll formed threads are cold worked by the rolling process and are both harder and smoother than cut threads.

In the US we can get 4140 B7 Heat treated all thread and cap screws. This material is about 125 KSI tensile strength. You have to have cutting tools to get a good machined finish. The hardness is about 35Rc so you can machine it with HSS.

[Frank46]

I've made stubby neck dies from 7/8x14 threaded rod I bought from a machine shop supply house many years ago, and case neck expanders from grade 8 bolts as well as threaded rod. To keep overworking the necks of the 7.62x54r cases I have one stubby neck die sizes down about .004" and one expander just puts a bell on the case neck. Except for the seating die in a three die set the neck and f/l dies rarely get used. Frank

[Ballistics in Scotland]

If you look closely at the threads of the Volvo studs you will see they roll formed instead of cut threads. The roll formed threads are cold worked by the rolling process and are both harder and smoother than cut threads.

In the US we can get 4140 B7 Heat treated all thread and cap screws. This material is about 125 KSI tensile strength. You have to have cutting tools to get a good machined finish. The hardness is about 35Rc so you can machine it with HSS.

You can form cases for a long, long time with unhardened dies, but there is some benefit in hardening of the cavity. Hardness and smoothness of the threads matters very little though, as they are immobile in use, and are probably screwed into cast iron, aluminium or zinc alloy.

[EDG]

I have no press that has cast iron, aluminum or zinc that makes contact with the die threads.
In fact the crappy threads on carbon steel all thread would probably damage both aluminum and zinc with heavy duty use.


You can form cases for a long, long time with unhardened dies, but there is some benefit in hardening of the cavity. Hardness and smoothness of the threads matters very little though, as they are immobile in use, and are probably screwed into cast iron, aluminium or zinc alloy.

[Ballistics in Scotland]

I have no press that has cast iron, aluminum or zinc that makes contact with the die threads.


I expect somebody must be buying them.

[TRX]

I bought a 3' length of 4140 7/8-14 threaded rod from Zoro Tools a couple years ago. It wasn't very expensive.

4140 machines nicer than mystery metal all-thread, and it's heat treatable.