Die question.

[blackbag 0]

I'm not sure if anybody here has an answer but I decided to post this question here knowing the technical experience of some of the members.

I was wondering if anybody who has experience with dies knows what would be the maximum variance in diameter of a bar stock compared to the diameter of the thread of the die.

I have bar stock that I need to thread in 1 3/16 -16 (which is about 1.188") however the bar is 1.200", my question is, is it safe to thread using a die or must it first be turned down to exactly 1 3/16?

thanks in advance

Edited November 15, 2008 by Adam C

[gunnysmith 4]

I usuallly follow standard machining practices.

Tha would be turning ot the threads major diameter.

It would probably put extra stress on the die if not turned, plus most external threads are flat on the top

[TonyRumore 1,332]

Maybe Bob Ash can chime in here, but my gut feeling is that you can get that to work as-is. You're only looking at .006" oversize per side. The die should be able to handle that.

 

Tony

[G O B 3,516]

If the die does not bind excessively, cut your threads, and then polish the thread points with emory cloth to round and smooth them.

[Gunfixr 76]

That is probably close enough to work, but it's going to put a lot of extra stress on the die, as well as making it that much harder for you. It will also make it harder to get started straight to the axis of the rod.

 

You'll want plenty of cutting oil, a special tapping blend would be worth the price in this instance.

[kingjoey 5]

It depends on the tolerance of the die. If you are using a split die you can loosen it up for your first cut then tighten and recut the threads. Being .006" oversize is enough to make the cutting edges on the die plow metal and bugger up the threads by swaging metal back into the cut. I would turn the bar stock to size first, it'll save you and your die a lot of grief. 16TPI is a pretty fine thread for 1-3/16", it wouldn't take much to bugger up the threads. I'm guessing you're working on an AR stock of some sort?

Edited November 17, 2008 by kingarmory.com

[blackbag 0]

I'm guessing you're working on an AR stock of some sort?

 

wow, good call just by thread size. I am currently working on a custom competition stock. It's all just theory right now, trying to work out details to see if the juice is worth the squeeze.

Thanks for all of the suggestions. Very Helpful A+++

[rd99fxdl 17]

Normally you need to be a hair under size,at 1 3/16 you'll probably be looking at about .005 under to get clean threads and to get them to fit good to your mating part.