Continuing Threads on an action screw

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Frazer

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Hello all, I need a shorter front bolt for a center feed, detachable magazine stock. The rifle originally had a blind magazine wood stock. The bolts I have on hand are not threaded far enough to work. I can grind a bolt shorter, but I can't add threads. I can shorten a screw, but my screws are not threaded far enough down the shank to tighten the action into the stock. Any ideas? What if I were to find the proper 1/4-28 tpi die, can I simply thread it on to continue the threads? Or would this not work? The screw is a stainless screw.

Thanks, Frazer
 
Sometimes the factory screw threads are rolled into the end and become larger to the correct size... the un threaded shank may be too small in diameter for good threads. It's worth a try or buy new screws...
 
Thanks for the prompt replies, I was concerned about the diameter of the section of the screw that is unthreaded at the moment. Ill have to check it with the caliper to make sure before I attack it with a die. I read somewhere about using 1/4'' grade 8 Allen Socket Screws as a replacement for the factory screws, has anyone ever heard of this or used it?

This is on a Stevens 200 btw, slowly getting new parts, When I got the new stock, my action screws dont work. I got the stainless ones with the stock and bottom metal and they are too long as well.
 
If you just need to add a few turns so that you can set the screw in far enough and the major load will be carried by the bigger oringinal rolled threads then the die will let you extend enough to seat the screw fully with no harm and you can use an undersize shank bolt. But if you'lll need to rely on this newly threaded portion and if it is undersize then you'll have to bite the bullet and go find some proper size screws.

And yes the allen screws in any of the cap, button, oval or flat head will work just fine as long as we're only talking about the 1/4-28 cases.

1/4-28 is the standard NF thread size. As such you should be able to fine an assortment of fine thread pitch screws in a variety of lengths at most decent hardware stores. This includes the allen cap style screws. But if you want an oddball head shape then you'll need to hit up a specialty fastener store. Or since you're using stainless screws phone around to a few boating supply centers that stock a lot of stuff for actually working on the boats. There's a very good chance they'll have the right head and screw length in 1/4-28 for you.

The good news is that because it's a standard fine pitch the die should also be available at a lot of the tool stores that stock any degree of threading taps and dies. They won't be all that good a quality but they'll only be $5 or $7 too. Just don't try to use an inexpensive die on one of the Grade 8 screws. It'll work for a while but the die will wear out and lose teeth pretty quickly once the sharpness wears off.
 
Thanks BCRider, when I look at the screw, it will retain an acceptable portion of original threads, you hit the nail on the head about continuing the threads so I can fully seat the screw. Good suggestion on the boating store, Ill see what I can come up with. Its not that I just dont want to order a new screw, I dont want to pay $10 to get a screw shipped to my door, especially when its only worth maybe a few dollars.
 
Well after mulling over my options and findoing out a few new things about taps and dies, I took at trip on my lunch break today to try and find some screws. I came up empty at Home Hardware and CO-OP the fellow at the co-op suggested the local bolt supply warehouse(I didnt even know we had one) I took a trip down and found some allen socket screws. They had a minimum purchase of 5 dollars so I got some of various lengths. Oh my savage should be happy now. Ill have to be carefull not to tighten them down too hard because I think a grade 8 screw is harder than the case hardening on the action itself isnt it?
 
A Grade 8 bolt isn't harder than case hardening.

I got some serious doubts that any Stevens 200 ever got case hardened, unless it was done outside the factory. If that was the situation, maybe announce yourself when you are at the range, eh. Case hardening the wrong steels can make bad things happen. Just sayin'.

It's pretty much an object lesson in everything being easy when you know how. If you start learning where to look for stuff like your bolts, you start finding out that you are not restricted as much as you would be if you were stuck dealing with "make, model,year" type stuff, guns or otherwise.

It's a slippery slope. Next you want a lathe. A mill. A shop to work in...:D

And books! Good ones! Gunsmithing, woodworking, machining, heat treating.... So many! :D

Cheers
Trev
 
Harder or not you don't want to overtighten any fastener. At worse you'll distort or strip the threads. And deformed threads don't self lock as well so it can lead to the screw walking out on it's own despite you regularly tightening it more and more. At best you'll introduce bending distortion into the surrounding parts and pull various points slightly out of alignment depending on the parts and design.

Maximum torque value for a 1/4-28 fastener varies depending on the grade and what it is set into. But for stainless, which is typically softer than Grade 8 and more like Grade 5 regular steel, the max value is in the 6 to 8 ft-lb range. That's precious little if you measure it with a torque wrench. You can easily exceed that value using a 6 inch long wrench and one finger. And in any real life situation I've never had to do anything up to a value that high. Especially if you're bearing down on wood without a metal anti crush bushing in it. Even for securing in metal I would pinch it to around 5 ft-lbs.

I've seen far, far more things damaged by over tightening than I have by under tightening. I'd suggest you start with it snug plus a little tweek and if it works loose then use a harder tweek until it stays done up. But as soon as you have to go white knuckle on more than one finger there's other issues at play. Think about it, on a 6 inch long wrench or allen key 6 foot lbs is the same as 12 lbs of force on the end of the wrench. If you can't easily get that much from one finger then you need to bulk up and eat your Wheaties. It's far more likely that you'll tend to overdo it and go well over the 6 ft-lbs and risk damaging the fastener or the thread in the part.
 
Ya it sure is a slippery slope, I already want a lathe, and a mill. I also want my brother in law to school me on how to use it all, seeing as he is a machinist... lucky sob.

About the tightening, I have always belived in a MAX of 65 inch pounds. I have a tourque wrench that is calibrated in inch pounds as well. My wife was asking me, "and why do you need this?" but now I have it so its all good! I usually only snug the screws up anyhow using my short (3'')allen wrench.

I wasnt sure if my stevens was ever case hardened, nice to know that it likely isnt.

I love CGN, soo much knowledge and everyone willing to share! I just have to stay out of the Equipment Exchange otherwise my bank account takes a hit, everytime it seems...I can stop whenever I like, I think
 
For the smaller stuff up to 1/4 inch I think inch-pounds is by far a better way to deal with torqueing. No messy fractions or decimals. And 65 in-lbs equates to just shy of 5.5 ft-lbs which is right in the happy zone that I like to use on 1/4 inch fasteners. I only went on my rant above because your questions about case hardening and thread damage got me thinking that you were breaking out the 2 foot long strongbar.... :D

Case hardening is merely skin deep and is used more as an anti surface wear treatment than to actually make a part stronger. On a case hardened part you should be torqueing a thread as though it's actually a regular mild steel part since the inside of the thread teeth ARE just the basic core steel. But at 60 to 65 in-lbs you should never find that you've distorted the threads.

As for the machine shop hobby be extremley careful. It's more addicting than the gun hobby by a long shot. And it's by far worse than guns for "I need this to make that". I've often spent longer making a jig or making a new tool that would let me make the part I need for whatever. And on more than one occasion I'd start making a tool or jig to do a job only to find that I needed to make yet ANOTHER tool or jig to make the tool or jig to make the part I needed. Yep....A guy can lose many an hour in a machine shop... many an hour.... :D
 
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