doublegunshop.com - home Forums General Discussion Classic & Custom Single Barreled Sporting Rifles @ doublegunshop.com Making Gun Screws:

A question for you gunsmiths and others who make screws on the lathe.

What sort of fixture do you use so you can remove the screw from the lathe, check it and return it to the lathe and continue cutting the thread?

Threading between centers is the easiest.
A collet stop and an index mark will get you close if you have to pick it up. Picking the thread up is pretty easy if you place a sheet of white paper under the thread & cutter and turn the light off that shines on the screw.

Clausing used to sell a poster that had the approximate compound depth for different pitches of threads.

For small screws, I use a couple of old screw plates that I picked up in yard sales.

Like James, I always pick up the thread 'manually'. I'm not fortunate enough to have a collet setup but doing it the old-fashioned way has kept me in good practice over the years. I always keep a (fairly) fresh paper towel handy on the back side of the saddle and it gives a very good contrast for the operator's eye.
Regards, Joe

Thanks for all interesting ways you guys do it. I’ve struggled trying to get the work back into the lathe correctly after trying it to see how it fit.
A while back I watched my friend John Wills make a screw and remove it and replace it in the lathe several times. Each time it only took seconds to be back cutting the thread.
John designed and made these little collars for ¼”, 5/16” & 3/8” screw stock. I’ve made one for ¼” and 5/16”. When you loosen the chuck and remove the work just replace it between the same lathe jaws each time and rotate the little dog against jaw No. 1 (on my lathe). The length is set by the back of the collar and rotation is set by the dog. Simple, quick and accurate.
John also cuts a screw slot at the back end of the stock for installing and removing the screw, also a good time to mark for the new screw slot.

That's really cool Michael - great post!

Michael
I like to use 5C collets either in a collet chuck or a 5C collet block. For standard threads (where you can get a die), I’ll make a couple of passes with a threading tool, then use a die mounted in a die holder in the tailstock, die will cut the threads to full depth.

I like to use 5C “Emergency” collets; they can be had in brass, steel and even plastic. You machine them to the size you need, you can even thread them.

I’ve got a few threaded for the standard threads that I use. Neat thing about a 5C collet block is that you can take it out of the lathe, thread the screw into a 5C collet then mill the screw slot.

Not sure what kind of threading tool you have, but I like the “lay down” type inserts, they make them in full profile, thread specific, but as the name says will cut the full profile of the thread, root and crest.

V/R

Mike

Mike, I have a 9" South Bend tool room lathe and use 1/4" bits that I grind myself.

It's an antique like the guns I wok with and my mill is a Burk.

While we are on the subject what steel do you use for gun screws?

I've about run out of screw stock and had it for so long not sure what it was.

I've ordered some 1144 and waiting on it before I make a set of screws for the Ballard.

Michael

For screws I like 12L14, believe it as originally developed as screw stock.

Machines like butter, beautiful finish, polishes, blues or case hardens nicely.

I've never really messed with Stress proof 1144, always figured it would be a bit too hard if case hardened.

V/R

Mike