Is 1/8" NPT the same as National fine thread? I bought a 5/16" tap for my juice pyro and sears had national fine and national coarse. I assume 1/8" NPT is the same as national fine, am i correct?

NPT is national pipe thread. It is different from course and fine threads.

So I need a 5/16" diameter, 1/8" NPT tap?

Just a 1/8 NPT. That is how it is reffered to.

Alright, thanks alot for your help.

I live in Pickerington. I think I have a 1/8" NPT tap laying around you could borrow if you wanted.

Thanks for the offer, I'm gonna be heading to my parents house and going back and forth the pickerington would cost more in fuel than the tap. You guys are great on here to offer something like that, thanks.

Now, is a 1/8-27 NPT the same thing?

Also, if i am right i found some charts online that say for a 1/8"-27 NPT tap the drill size is "R". I know edge says to drill a 5/16" hole so what does R mean? sorry just trying to educate myself on drilling and tapping.

Thanks for the offer, I'm gonna be heading to my parents house and going back and forth the pickerington would cost more in fuel than the tap. You guys are great on here to offer something like that, thanks.

Now, is a 1/8-27 NPT the same thing?

1/8-27 NPT is exactly what you are looking for...
If you're going to a Napa for it, the part number is T-301 ;)

on edit: (since you edited first ):h ) the "R" drill bit is just a shade larger than a 5/16 drill bit... .3125 (5/16) an "R" drill bit is .339 a 5/16 will probably work, but drilling the hole with an "R" bit will make tapping a bit easier (less material to cut threads into)

lol, thanks for noticing the edit. Thanks everyone for the help, i feel educated on the measurements in tapping):h .