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

[BCRider]

Background;

I've got a trio of old Remington rimfire pump action rifles. The screws that hold the pump handle to the magazine tube which cycles the action use two VERY fine thread screws. These screws apparently love to leap away for freedom when no one is looking as between the three rifles I've got ONE proper size screw... ONE! Someone Bubba'd other sizes to sort of work and luckily didn't damage the proper thread in the magazine parts. And one came with NO screws at all... But I got it for a low price as a result.....

So from measuring it didn't seem quite right but I thought they might be #10-48. Ordered a die and it came. Made up a quick test screw to try and no di....ce…. Thread is too big to fit. So I'm thinking that 120 years ago when the Remington 12 was designed that 3/16-48 was a thing. But no more. And if you're thinking that it may be British or similar think again. I can find no reference to anything of the sort in the Whitworth or BA line. But I did seem to recall that there was another series?

The Tale of Woe;

So after reading the recent thread by the guy that single pointed a 0-80 nut I thought WTH, let's DO THIS! ! ! ! I made a boring bar with a threading tip and made the die. Pictures below show it just after cutting the relief holes in the mill. BUT.... the tiny little boring bar's tooth didn't harden as well as I'd hoped. Or even with care in the grinding perhaps I took the temper down too far. It went dull and rounded the tip even in the three passes of a few thou each needed to form the thread. I suspect that the hardening took away too much of the surface carbon from the thin edge. So the thread that came out was poor and deformed and didn't fit the other parts worth a hoot. And on top of that in trying to pinch the die inwards to make it work I managed to crack off one of the ears at the chip holes...…

The Future;

I think this time I'm going to do a tap which I can fit to the rifle part and then use that to cut the die blank. But that's for another day....

TBC....

[epicfail48]

Wait... if youre single-pointing the threads for the die, why not single point the screws you want to make with the die? Im a bit confused by the order of operations here

[Ringo]

have you tried this?

https://www.gunpartscorp.com/gun-manufacturer#letter-R

[David Powell]

I am lazy, Instead of trying to make tools to cut internal threads I look through my collection of damaged or worn taps and choose a suitable size one with the thread angle I want ( 55 0r 60 degrees) and grind all the bad bits away until I have a tool with just one good cutting tooth and then organise a holder and get on with the job. Really only a useful hint on short threads. Regards David Powell.

[nickel-city-fab]

Hold on before you go too far -- I might have a die that would work. For some reason I have a type of OCD that compels me to collect every possible thread. Including a set of very non standard antique machine screw dies, in fractional sizes that do not match anything published today. Give me an hour or so and I'll make a list of what I have and post it ok?

also -- are you sure about your thread angles etc? They might have used something like 55 deg instead of 60

[nickel-city-fab]

Do any of these sound like they'll fit? If you think one of these might work, PM me and I'll get it in the mail soon as I can afford postage.

1/16-64
3/32-48
1/8-40
7/64-48
3/16-24
9/64-40
5/32-36
7/32-24

[J Tiers]

When making small tools, "decarb" is a major issue. All the small features get the carbon burnt out of them and you are left with a pretty part that is worthless for the purpose intended.

Time for the stainless wrap, with a scrap of paper in with the part, and maybe the use of air-hardening steel.

[MrWhoopee]

I am lazy, Instead of trying to make tools to cut internal threads I look through my collection of damaged or worn taps and choose a suitable size one with the thread angle I want ( 55 0r 60 degrees) and grind all the bad bits away until I have a tool with just one good cutting tooth and then organise a holder and get on with the job. Really only a useful hint on short threads. Regards David Powell.

This has been my approach. As long as the pitch of the tap is greater than the thread to be cut it is by far the easiest and most accurate way to produce a small threading tool.

[Rich Carlstedt]

BC
" Thread is too big to fit"
You have a few options , first is to confirm it is 48 TPI
There were no "thread Standards" in 1900 as we now have and each Mfg had their own until 1906 ~ ( ANSI) and even then, the change was slow
( The USA went Metric over 100 yrs ago I understand , and see where that has gone ?)
First option:
So, Does the screw you have (OEM) fit the die ?
Have you tried it ?
Is it loose in the die about .003" ( 3/16 versus a 10 diameter 48 )?
Is the die that you bought, a split die ?
If split, tighten it up to cut a smaller thread.
If the die will not tighten or is solid, split it with a dremel abrasive wheel
If you break it ( so what ) then place the screw in the die pieces and measure the diameter - then make a die holder for that size.

Second option
Make a new die, only don't waste time with with making a tool bit (This is a old timers trick)
Drill your tapping hole as usual
Use a smaller tap ( ie 6-48, 5-48- 4-48, 3-48) as your threading tool. ( keep it square !)
Clamp a tap with one flute at C/L height as you would for a boring bar .
Set your change gears for the matching thread and make your normal several passes to size
You will be cutting with a single flute doing the work and using a perfect tooth form.

Rich

[BCRider]

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....

[nickel-city-fab]

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.

[BCRider]

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.

[754]

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

[Rich Carlstedt]

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

[nickel-city-fab]

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.