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Tried to make a special size die.... a tale of learning through failure.

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  • BCRider
    replied
    The way the screw seats it does not bear down on that shoulder. Instead the head comes to rest against a step in the ID of the steel bushing set into the wood of the pump action fore grip. It only screws in about 2.5 to 3 turns.

    But it would have been a good call otherwise. And to be fair it sure LOOKS like it should bear down on the shoulder.

    The small number of turns obviously puts a fair amount of stress on those few threads. Which would be why this is the better formed of the two screws I've got and the other from a different rifle has the crests of those last few threads that are used fairly badly worn.

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  • J Tiers
    replied
    You might have to single point that. There is no run-off on that thread visible, and a die will generally not thread right up to a shoulder, as appears to exist at the end of that thread.

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  • nickel-city-fab
    replied
    Wow I didn't realize it was that bad lately. The US is a lot more paranoid than they were when I was a kid, we used to cross the border for a dime and party all night no questions asked. Of course that was 35 years ago.

    On the other hand, if you manage to figure this out, I can see how you could make a nice tidy profit on the side, by making oddball screws for the gun community in Canada!

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  • BCRider
    replied
    Originally posted by Rich Carlstedt View Post
    If you enjoy making odd threads, look into getting a Geometric Head.
    They have some really weird pitches available and what is neat is that all thread diameters are fully adjustable
    So a thread die of say 5-40 can be made to 4-40 or 6-40 in size as it is adjustable for Over/Under sizes
    Rich
    It's not that I enjoy it. Rather that some of the older firearms simply call for odd sizes. This need for what seems like it is 3/16-48 being one of them.

    I had a look at some listings for such heads found on Ebay. And I gotta say that it seems like a nice bit of kit. Looking on Ebay it seems like there's a couple of sizes available at a quick glance. I think I'd be looking for the smaller size for finer threads if this is the case. Something for the future... But for now I need 5 of the little devils shown below and two of a slightly longer size but same thread and diameters. So I'm going to keep going with the die making project.

    I actually did check with my local gunsmith and he was saying that Numrich is still not selling directly to Canadians. This really applies to barrels and receivers but US Customs is still seizing and laying charges over ANY firearm parts. Screws of this sort included. I'm not willing to take the chance since it would strongly affect my ability to travel to the US.

    My gunsmith buddy can and does order from Numrich on occasion. But there's a lot of added cost to process the export license and brokerage for such parts. If I did this myself my 7 screws would be well over $100 due to the cost of the parts, a miserable exchange rate at present plus the added cost of the export license and brokerage. Such is the cost of buying gun parts that need to be delivered out of the US at the moment. And while I could wait until he orders parts and group the order it would still be something around $10 to $15 PER SCREW.... And some many number of weeks until I get them since he only orders from Numrich about 3 or 4 times a year.

    Here's the little devil so you can see the size....

    Click image for larger version

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  • nickel-city-fab
    replied
    Originally posted by Rich Carlstedt View Post
    If you enjoy making odd threads, look into getting a Geometric Head.
    They have some really weird pitches available and what is neat is that all thread diameters are fully adjustable
    So a thread die of say 5-40 can be made to 4-40 or 6-40 in size as it is adjustable for Over/Under sizes
    Rich
    Yep, same idea as the Greenfield dies. A little micrometer screw moves the cutting edges in or out. That's one reason why I like them so much, you can "sneak up" on a close class of fit. The other advantage is that they can be re-sharpened easily with a slip stone.

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  • Rich Carlstedt
    replied
    If you enjoy making odd threads, look into getting a Geometric Head.
    They have some really weird pitches available and what is neat is that all thread diameters are fully adjustable
    So a thread die of say 5-40 can be made to 4-40 or 6-40 in size as it is adjustable for Over/Under sizes
    Rich

    Leave a comment:


  • nickel-city-fab
    replied
    Originally posted by BCRider View Post

    Old mart, yes I can cut the thread on each screw. But we're talking about literally 5 turns of thread at 48TPI up to a slightly larger point. And I'm looking at doing it a dozen or so times to make what I need for myself along with a few spares in case another one jumps ship in the future. So all in all it would be nice to just make a die and do a mini production run instead of single pointing each one.
    Cool. If I had to single point that, I would just turn the chuck by hand. I'm really challenged by the smaller stuff.

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  • BCRider
    replied
    Originally posted by nickel-city-fab View Post
    I do wonder if that 7/64-48 die could be opened up to the 3/16 that you need, since they are 2-piece adjustable (look closely, those are Greenfields)... will have to experiment. If I can make it work, I'll make you a threaded rod, 3/16x48.
    I had to go back and look at the picture again. Yeah, that's pretty sweet that the dies are almost like little holders for the threaded inserts.

    Thanks for the offer but let me try the self made tap option first. I've made a few specialty taps over the years and they all went fine. And in truth I'm shifting gears a bit and now I feel that I'm better off to go with making a tap to make the die anyway. I'll do the three wire thing on the one good screw I've got to measure the tap I make. And that way I know that the die I make with the tap will be good.

    The big challenge is that this will be the finest thread I've ever done so I will need to take it in small steps.

    Old mart, yes I can cut the thread on each screw. But we're talking about literally 5 turns of thread at 48TPI up to a slightly larger point. And I'm looking at doing it a dozen or so times to make what I need for myself along with a few spares in case another one jumps ship in the future. So all in all it would be nice to just make a die and do a mini production run instead of single pointing each one.

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  • old mart
    replied
    You can single point any size of thread you like as long as the lathe can manage the thread pitch. Decent thread charts list the depth of thread per pitch and type, so you know how deep to go. I just cut a thread on a 1" UNF bolt shank, and fortunately checked the pitch first. I was expecting 12tpi, but it turned out to be 14tpi and on a genuine made in the USA bolt.
    Last edited by old mart; 03-12-2020, 03:44 PM.

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  • nickel-city-fab
    replied
    I do wonder if that 7/64-48 die could be opened up to the 3/16 that you need, since they are 2-piece adjustable (look closely, those are Greenfields)... will have to experiment. If I can make it work, I'll make you a threaded rod, 3/16x48.
    Last edited by nickel-city-fab; 03-12-2020, 03:31 PM.

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  • Rich Carlstedt
    replied
    If you subscribe to Home Shop Machinist, the sponsor of this website, maybe you have some back issues or a friend that has them ?
    In January of 2008 , Jerry Kieffer wrote an excellent article on making taps and dies in the home shop
    His techniques work ----and some are not ordinary , but should work for your application
    Rich

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  • 754
    replied
    Just single point the screw you make, it's not like making a micrometer..

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  • BCRider
    replied
    You might well be on to something there. But an initial check for sewing machine screw sizes didn't show me anything along the lines of 3/16-48.

    The best chart on the topic I found after a dozen links was THIS ONE. There's a few 48tpi sizes listed but none around 3/16 give or take a 1/64.

    But the chart at the bottom of that link does list "thread tap sizes" and it covers most or all of the oddball sizes you have listed above. Seems you have a couple of sewing machine tap and die sets there.

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  • nickel-city-fab
    replied
    Ya know, it occurs to me to wonder if it isn't a odd sewing machine thread, if remington was producing parts for those at the time.? dunno.

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  • BCRider
    replied
    Epic, right off the bat I need 5 of them. And I wanted to make a few others both for myself and possibly to supply to the other vintage gun owners out there that are in the same situation. So a bit of extra work up front to make the die then go on from there. That's a lot of single pointing on parts that are not much bigger than a house fly. Making the die up front is just a lot less fussy in the long run.

    Ringo, I know about them and COULD get them that way. But where's the home shop fun in that? Last I read Numerich wasn't shipping to Canada though other than through registered gunsmiths. But one of those happens to be in the cowboy action side of the sport so that is and was always an option. But I wanted to have a go at learning the ins and outs of the small threads and hardening issues related to smaller size things like this.

    NCF, thanks for checking and that's a pretty wild set of old size dies you have there. Certainly supports the idea that the old thread systems were a bit messed up. Sadly you don't have what I need. I'm also guessing that those sets date back to roughly the same 100 to 120 years ago as the rifles I've got.

    Rich, it's definitely 48TPI. But it's tough to spot the angles since the one screw I've got when seen at high magnification is pretty badly worn. It's from one of the rifles that dates to the 19 teen years. So there's a touch of guess work involved with the actual crest and base diameters. Hence why I originally got the #10-48 only to find that the resulting thread was a touch too big to fit the magazine tube on the gun.

    JTiers, I'm sure you're right about the de-carborizing. Under high magnification in the post mortem I saw that the point and area just below the point on the boring bar cutter was rounded over after just the three passes. And while the screw was a touch loose in the die after hardening the die the screw was even more loose. And after it cracked in two from trying to spring it inwards to cut the 10-48 version down a little and I looked at the teeth they seemed eroded with a coarse finish like they had been etched. Likely because I let the die heat soak for about a minute in the presence of the silver solder flux. I need to get some proper boric acid I guess.

    I've got some thin stainless steel shim stock. Not much thicker than a foil. I guess I'll give that a try.

    The other "learning issue" that occurred was that the silver solder flux, which might or might not be boric acid, ate away at my little soup can forge badly. So now I need to make another one of those too... <sigh.... > It's a cheapie, quickie sort of thing that used plaster of paris, sand and perlite to create a forge for doing small parts like this. The material worked like a charm for a dozen or so things up until yesterday's debacle..... And now there's a big sticky messy cavity where it dissolved away.

    I have to admit that just ordering from Numerich is starting to sound better all the time....


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