6mm not M6 thread?

[Pepster]

Hey all,

Ok, if you're not mechanically inclined, this may not be the thread for you </disclaimer>

I've been trying to figure this out for some time, starting back when I was team armorer in college and our M6 thread taper wouldn't thread onto a (good) 6mm tang (I would thread the tapper on first, then cut the tang). I also noticed a standard M6 nut from home depot wouldn't fit the tang either. I kept standard nuts around to sort out the 6mm vs. 12-24 mysteries that cropped up with our eclectic armoring closet.

So recently, I got two practice blades, that appear to be 6mm.. (as in, my 6mm inside hex nut fits fine) but when I try to put a standard M6 nut on, they won't fit. Is the thread on a 6mm tang different from a standard metric M6x1 thread? Has anyone run into this issue before?

FYI - I've never had this problem with a 12-24 tang or pommel, they all work interchangeably.

Thanks guys
- Pepster
( New to the board, plenty of questions )

[Pepster]

Update:

I went down to the sotckroom at work, and got an M6x1 bolt. So now I have two nuts (M6 and Pistol Grip Inside Hex Pommel), and two threads (Tang and M6 Bolt).

The Pommel fits the Tang
The M6 does not fit the Tang
The Pommel fits the M6 Bolt

I assume the two M6s fit together, but the nut is at home, and I can't track one down here.

Also, the M6 bolt has 25 thread turns in one inch, if anyone is interested.

I'm still no closer to finding out WHY an M6 nut won't fit my tang....

Thanks,
- Pepster
Who loves a good mystery

[Artisan]

By "tapper" you mean "DIE" ? Was the Die worn out? Was it a M6x1 die, or some other (6x1.5 or 6x .8)? Also some dies are adjustable: there is a set screw that forces a split in the die apart to allow you to tweak the tolerance of the thread. There is also a remote chance that the die was for some other type of special thread profile, not the standard 60 deg.

Also, the M6 bolt has 25 thread turns in one inch, if anyone is interested.

yup - if measured with a thread gauge, actually its 25.4 - but that shouldn't matter. There was a recent thread here about getting 12-24 nuts to work on M6 tangs.

Try running a M6x1 tap through the M6 nut and see what you get. If it cuts some material, either the nut wasn't M6, or it was poorly made - maybe too much plating, etc...

[Pepster]

The M6 die (sorry 'bout that) I referred to was actually two. One was mine, the other was the schools's machine shop (standard automotive set). I can not longer speak for what threading they had, as I'm in CT and the tools are in PA. Neither one threaded on the tangs of 6mm santelli blades past a turn or two.

I'll see if I can find an M6x1 tapper. You're fairly certain that 6mm tangs are an M6x1 thread?

-Pepster
- Who needs new threads.

[Mergs]

The other alternative is to get at thread guage and verify that the tangs are threaded to M6X1. One of the other problems that you can run into is that the preservative that they use on the threads can cause a build up that will not allow close toleranced dies/nuts to go on easily. I normally find that if I run a M6 die (which is nominally 6mmx1) down the threads, i.e. chase them, I just get gunk, not metal.

just my $.02

[Pepster]

Just ran down to the machine shop, and got a M6x1 Die and tapper. The tapper threads beautifully into the 6mm pommel nut. The Die doesn't seem to happy with the M6 bolt (odd, they're the same thread). I'll try them on the other two when I get home.

[DHCJr]

Does the die thread onto the tap? As said before the die adjust and it could be poorly adjusted. The tap can not be adjusted and you can notice more easily if it is worn.

[Pepster]

Originally Posted by DHCJr

Does the die thread onto the tap? As said before the die adjust and it could be poorly adjusted. The tap can not be adjusted and you can notice more easily if it is worn.

Nope, just tried it. They don't want to thread together.

If they weren't both labeled "M6 X 1.0" I would doubt they were the same thread. However, the Die is not adjustable.

-Pepster
- Who has nearly half his posts in this thread

[pkt]

The things one can learn on this forum is amazing.
Thank you all,
PK

[Pepster]

Ok, now I've got everything tested.

I have three each of items that can be considered "Male" and "Female"

Male:
M6x1 Bolt from hardware Store
M6x1.0 Thread Tap
6mm practice Epee Blade Tang ($7 special from blade!)

Female:
M6 nut from hardware store
M6x1.0 Thread Die
6mm inside Hex nut pommel
----------------------------------
Results:

The Pommel nut threaded onto all three male pieces. There was some play in the bolt, leading me to beleave it's a very coarse thread.

The Hex nut would not fit the Tang at first (remember my first post?) but fit the M6 bolt. It DID thread onto the Tap, but it took some work. I did it with my fingers, so it wasn;t too tough. After working it 4-5 turns onto the tap in each direction, it fit the tang beautifully.

The M6.0x1 Die didn't fit anything... I could work it onto the M6 bolt, but it wasn't easy, and became harder past the first few turns.

Conclusion:

6mm Blade tangs translate to a standard M6x1 thread, although it may be a bit coarse.

Sub-Conclusion:
I have too much time on my hands

Followup question:
Anyone attempt using a standard hex nut (13 cents) in place of a pommel nut ($1.50)? Any suggestions or comments?

Thanks everyone!

-Pepster
- Who is REALLY getting to like this board.

[Artisan]

Originally Posted by Pepster

Ok, now I've got everything tested.


Followup question:
Anyone attempt using a standard hex nut (13 cents) in place of a pommel nut ($1.50)? Any suggestions or comments?

Thanks everyone!

-Pepster
- Who is REALLY getting to like this board.

Search the [board] threads for the postings by Mergs about using 12 x 24 standoffs instead of the $4 pommel nuts from fencing vendors. Standard nuts usually won't fit into the counterbored hole in most pistol grips, with enough room to get a socket wrench on it as well

[drew1]

By some chance are either the blade or pommel from Germany? The Germans have a taper thread similar to our US NPT pipe thread except it is metric. I got on this Forum while searching for a source for metric taper dies.

If this is what your thread, is it would be M6 X 1 Keg. This would be the male thread. The females are straight in stead of taper.

[Purple Fencer]

Originally Posted by Artisan

Search the [board] threads for the postings by Mergs about using 12 x 24 standoffs instead of the $4 pommel nuts from fencing vendors. Standard nuts usually won't fit into the counterbored hole in most pistol grips, with enough room to get a socket wrench on it as well

I've been doing that for a couple of years now...having standard coupling nut re-tapped to 6x1....$2 each (I gotta cover teh costs somehow)

[battleaxe]

I've seen similiar problems with a few blades. I just assumed someone used a worn die to thread the tangs during manufacturing. I rethreaded it with a good 6x1 die.

[Mergs]

Originally Posted by Purple Fencer

I've been doing that for a couple of years now...having standard coupling nut re-tapped to 6x1....$2 each (I gotta cover teh costs somehow)

Oh, you have, have you? Where's my royalty check, damit?!?!???!?!! Standard industry rates apply. Oh. Wait, they're on strike aren't they? Damn.

As for the other problem, one thing to make sure you check for is whether or not you have a coarse threaded nut. Fasteners usually come in fine or coarse threads. So an M6 nut may not necessarily be M6 x 1. That said, in doing a search of my references, I don't see that case for metric threads, so I'm stumped too. Unless there is a difference in the class of threads, which means that for precision parts the thread diameter (in the case of metrics) are slightly larger and therefore fit tighter.

Yes, we do have too much time on our hands!

[Purple Fencer]

Originally Posted by Mergs

Oh, you have, have you? Where's my royalty check, damit?!?!???!?!!

Your nickel's in the mail....

[Nolano]

I once repaired an epee tang that had broken by TIG welding an m6 stainless bolt on... Worked perfectly. The blade is still in good shape, although sometime in the few weeks that the tang was broken, the wire got damaged.