What does the 13 refer to in this half inch die for threading a rod mean? I believe those numbers after the inch sizes vary and wondering what that number means. Does that number refer the number of threads in one inch? I believe some dies different sizes have 14 or 20 stamped on them also.

Thanks

The second number is threads per inch.

There is standard, fine, coarse, extra fine for each diameter.

For SAE sizes it is threads per inch. On metric sizes it is the distance from one thread to the next. It is refered to as thread pitch.

yup threads per inch SAE

pitch metric

13 would be considered coarse a typical carige bolt in 1/2 inch would be 1/2-13

because it changes by how big around your fastener is 1/4-20 is a typicall medium coarse fastenter it is very common

fine like 1/2-28 this is what 223 barrel muzzles are most commonly threaded

there is a very fine 1/2-36 right now if your trying to beat the SBR ruling you might be looking for a 6 inch KaK can this is a muzzle device they sell for about 35 dollars and it will take your 10 1/2 inch AR barrel to 16"
anyway all the 1/2-28 are sold out but you may see 1/2-36 i have no idea what used 1/2-36 but it isn't very common on ARs

any way if you thread one of these on , drill a small hole in the the bottom of the muzzle device put a pin that goes into the threads so it can't turn , then put a tack weld on that pin so it would have to be ground off to be removed they consider that perminent enough that it is no longer a short barrel.

a lot of people are doing this to not become a felon while the mess gets litigated , then if the courts tell ATF that they are way over stepping like they are . a grinder and you take that 35 dollar muzzle device off and put your original back on.

that seems very cheap compared to 10 years in prison and 250K in fines

Great! Thanks for that help. I have to thread a 7/16 rod for my shallow well which I have and old long handle hand pump on it. I have some work to do on it as soon as I can do some hand digging. I'm trying to get the threading done now.

So, my question for 7/16 inch what the die would be I would need to buy for that? 7/16-13 or 14 or what would be your guess.

Don't guess, google SAE Standard threads and it will tell you exactly.

Someone explain NPT and we'll have em all covered.

Since Pete brought up rifle stuff.
Mcgiver moment.
I got a bullet stuck in my flint lock. Was able to remove ignition nipple,
thread in a zerk fitting,
and pump the bullet out with grease gun.
Then blew grease out with air and smeared it onto log splitter mast.

7/16th national course is 14 tpi.

^^ not guessing just wrong word used. I do go to SAE and i believe I will need 14 turns in one inch measurement.

Thanks

If you are threading into the pump and not a nut, you can check the thread in the pump with a bolt. That way you will know what you need for sure.

also a bunch of gauges that you can use to be sure before the drive to the hardware store
https://www.amazon.com/Marine-Bolt-...6&hvtargid=pla-571118525415&th=1

when thinking about the price of the gauge ask if this saves X trips at current price of gas how long till it has paid for it's self. depending if you live next door to the hardware store or not it might be a week or less

most older hardware stores have a board with one of each size nut and bolt so you can figure out what you have before you rifle through all the bins

look for the Joining nut it is a nut but about an inch long for joining 2 thread rods , these work great , most TC guns are 1/4-28 and most of the spanish guns are 6mm-1pitch I have one of each size in my kit , it chucks up in a drill then you can use your cordless drill as a micro lathe with a chainsaw raker file small fine flat file with smooth edges.
you can tune your nipple to the caps you are using so they go on with thumb pressure and are a bear to pull back off.
as you use the rifle a bur forms where the nipple starts to peen , a light touch with the file while spinning takes this bur right of and has you running one nipple very long time.

nipple tuning gets extra important beyond just it goes on and fires every time on cap and ball guns , you want those nipples to stay on through recoil , no one wants chainfire.

True and some great advice once again, so much knowledge here. I did thread some 1 1/4 well pipe and that went good. I still need to do one more of them when weather gets better in spring.

they are a fraction - number of threads per inch the difference is they are a taper so they get tighter as they go further in

common sizes are

1/4"-18
3/8"-18
1/2"-14
3/4"-14
1" -11 1/2
1_1/4" - 11 1/2
1_1/2" - 11 1/2
2" - 11 1/2
2_1/2" - 8 threads per inch

WOW…..LOL

No nipples on a flinter.

An antique hand pump could still have what we called jet rod threads, I still have a few of the couplers in my possibles somewhere.

That's a new one! Jet rod? Are they coarse like acme threads?

The UNRC for 7/16 is 14
The UNRF for 7/16 is 20

The coupler are 7/16 inch and it is a matched thread to the cylinder/plunger and thread on perfect. I now have to thread the 7/16 inch rod to make this connection from cylinder to rod extending upward to exposed rod for handle operation. A long story and not sure if most can even figure out what I'm trying to do.
I have been using a pitch pump and could draw 5 gal in just less then 60 seconds. This longer cylinder will produce quantity over the very short stroke of the pitcher pump.

I have the pump jack/wooden pitman arms, gear box and gas engine and I will get that going soon also. It is in a remote area without power so will install the small gas engine to well extract water.