Dies won't thread into Press

[INTJ]

I just received my Prazipress and it is a marvel of German quality. My Redding, RCBS, and Forster 7/8-14 dies thread in fine, but my Harrells and Whidden dies won't. I assume the Harrells and Whidden dies are purposely made with tighter threads.

I have an e-mail into Prazipress to see if he has a press insert that has a little looser threads for use with the Harrells and Whidden dies. If he doesn't then I need to figure out how to get these dies to fit.

I suppose I could put them in my lathe and try to deepen the threads some. I don't know if the dies are hardened on the threads and if that would put a strain on my carbide threading inserts. I have never tried to deepen existing threads.

I guess I could also buy a 7/8-14 die to deepen the threads on the Whidden and Harrells dies but I don't know how successful that would be.

I am not excited about the idea of using a 7/8-14 tap in the press insert, and I really don't want to try and machine my own insert.

Thoughts?

 

[Doug Beach]

If the existing press insert is easily removed, making a new insert sounds like the easiest, and least potentially destructive path. Worst case, you kill a couple hours on the lathe, and maybe learn something.

 

[jackson1]

If you can determine your press insert has 7/8"-14 threads in it. Why not just run a 7/8"-14 tap thru the existing threads. Maybe a little re-tapping could solve the problem (a little thread clean up). 7/8-14 taps are common, but a little pricey, but with what you have invested in your press, reasonable. If your insert was made on a CNC machine, the conversion from one thread type to another can get lost in translation (meaning maybe a little small).

 

[liljoe]

I wouldn't want to run a tap into a press I just paid about $1000 for.
I ran into this situation a few years ago with my Harrells press. None of my dies made from Newlon die blanks would fit. I had to use a different press for those.

Joe

 

[Herzo]

Find an old toolmaker who can use wires to determine how much oversized the Harrels & Whidden dies are. If you are only talking a few tenths, you could probably purchase a 7/8-14 bolt and use it as a lap to enlarge the threads in the press. The dies will be too hard to recut the threads and chances are that the female threads in the press are also.

 

[Walt Krafft]

Carefully examine the root of the thread in your press. They could have chipped the insert when it was threaded. If that was the case running a tap into it is an easy fix.

 

[Dean Slater]

I just received my Prazipress and it is a marvel of German quality. My Redding, RCBS, and Forster 7/8-14 dies thread in fine, but my Harrells and Whidden dies won't. I assume the Harrells and Whidden dies are purposely made with tighter threads.

I have an e-mail into Prazipress to see if he has a press insert that has a little looser threads for use with the Harrells and Whidden dies. If he doesn't then I need to figure out how to get these dies to fit.

I suppose I could put them in my lathe and try to deepen the threads some. I don't know if the dies are hardened on the threads and if that would put a strain on my carbide threading inserts. I have never tried to deepen existing threads.

I guess I could also buy a 7/8-14 die to deepen the threads on the Whidden and Harrells dies but I don't know how successful that would be.

I am not excited about the idea of using a 7/8-14 tap in the press insert, and I really don't want to try and machine my own insert.

Thoughts?

I would be interested in hearing what you find out from Prazipress about this. I received my press Friday and I am experiencing the same thing with my Neal Jones sizing dies. All my other dies (Lyman, Redding and Whidden) thread in fine but Neal's wont.

 

[NorCalMikie]

What's the difference in measurements between the RCBS, Redding and Forster compared to the Harrell's and Whidden?

 

[Kratos]

I just went through this as well. The guy who makes the Präzipress says the bushing is tight and he can make a looser version but it does take several months to get export permission from Germany.

He also said the bushing is hardened steel and he didn’t think retapping it would work well.

Oddly, all of my Whidden seating dies fit, but most of the click adjustable sizing dies don’t.

 

[NorCalMikie]

Sounds like it's time to find a local "machinist" that knows his stuff and can punch one out for you?
Might even be a good idea to have the man do a "few" so other folks that have the same problem can get the fix too and, make a few $$$ at the same time?
If you're going to bother to do one, make it a few.

And just having a lathe doesn't make you a machinist. Know who you're dealing with.

 

[DirtySteve]

Instead of running a Tap down the press and changing dimensions on the 1K press, why not run the offending dies through a die to recut or clean up those threads.?

Just a thought I can say I have no machining experience what so ever..

 

[moondog]

I kinda ran into the same thing on a Large body Warner Die. Got a Redding Big Boss. Took the bushing out, cleaned the threads and the Die was really tight going in. I blued the threads and determined the points on the threaded portion of the press were proud. I used a drum bit with sandpaper on it and just ran it in and around just taking the edge off.
Fits perfect.

 

[INTJ]

Thanks for all the replies. Thomas is sending me a looser die adapter, though it will take a while. In the mean time I'll put one of the dies in the lathe and deepen the threads until it fits my current adapter. Just like fitting a barrel to an action......

 

[rwk]

metric

 

[INTJ]

7/8-14

 

[M-61]

Response to #14

On Ultimate Reloader:
Präzipress

• Press assembly
• Handle, washer, nut
• Owner’s manual
• Combo wrench
• Spanner wrench (for bushings)
• 1 1/4″ 12 TPI bushing
• 7/8″ 14 TPI bushing (installed on press)
• Mounting bolts (countersunk), washers, nuts
• Primer catch bottle

 

[NorCalMikie]

I think I would be looking at "high points" on the threads, especially if one brand of die fits and another doesn't. That's why I thought about measuring and comparing the difference between fit and no fit.

 

[INTJ]

I measured diameter and both the Whidden and Harrells are smaller in OD than the ones that fit, so it's the thread depth that's the issue.

 

[Rockchuck]

Give carlsbad a shout he made me some parts very very good work.

 

[Herzo]

I measured diameter and both the Whidden and Harrells are smaller in OD than the ones that fit, so it's the thread depth that's the issue.

Pitch diameter is oversized...check with wires

Find a 7/8-14 grade 2 bolt if you can, it will be soft enough to accept lapping compound. A grade 5 or 8 will be harder and will not take the compound as well. Most bolts are cut to a 2A tolerance giving room for lapping compound to work. I would grind some flats 3 or 4 places around the bolt to allow the lapping compound to feed. I would probably start with some Clover 320. You are not going to have to remove much material from the internal thread. Keep the process well oiled any engine oil will work. Knowing the Germans, they may well have cut the internal thread to a 3B or tighter.