26 TPI nipple

[Canute Rex]

I have read a few old threads about threads - specifically nipple threads - and I still have a question.

I have an 1867 target rifle with a nipple that seems to be threaded 26 threads per inch. Too fine for 20 and not fine enough for 28. Apparently fairly standard back then. The nipple is in fine shape but the diameter of the cone is too small for even #10 caps. I have to squeeze them oval or they fall off. I could drill out the nipple seat and thread it larger, but I'd like to leave the rifle as-is if possible.

Are there any 26 TPI nipples out there for sale? Thanks.

 

[Metalshaper]

sounds like you might be dealing with a metric version??

 

[Phil Coffins]

In 1867 there wasn’t standardized threads, each gunsmith could and would make what ever he deemed right. If I had a old rifle and it required a threaded part I’d make it to fit the gun rather then alter an antique. A machinist or real gunsmith can do this but it won’t be $5 or $10 dollars. There’s plenty of guns to shoot but less and less antique ones.

 

[SDSmlf]

Are there any 26 TPI nipples out there for sale? Thanks.

You don’t say what diameter you need, but places like TOW have 26 pitch nipples of various diameters if that is what you actually need. You will need to provide real (diameter and pitch) measurements or a sample for them to check and compare with.

 

[Notchy Bob]

Metric threads that are 1mm peak-to-peak are really darn close to 26 TPI. I've been cleaning up the locks on two old Springfield rifle muskets, and found the internal lock screws are all 26 TPI, and larger than a #10 but smaller than a #12. I recently found in the back of an old Dixie Gun Works catalog that 19th century American military guns typically used a lot of metric screws, evidently a holdover from copying the French Charleville muskets in the 18th century. In any event, Turner Kirkland said my Springfield lock screws are 5x1.0 mm. I just got a metric Screw Checker and haven't had time to verify this yet.

Anyway, you may be dealing with a metric nipple. Or maybe not... It looks like @SDSmlf has found some nipples that really are 26 TPI.

I would agree with leaving the antique as it is, and putting in the effort to find a part that fits it.

Good luck!

Notchy Bob

 

[Rudall]

19th century American military guns typically used a lot of metric screws, evidently a holdover from copying the French Charleville muskets in the 18th century.

That sounds a bit suspicious as the metre wasn't defined until 1793.

 

[nhmoose]

20 not quite fine enough, 28 to fine. Midway is 24 TPI eh?

 

[Notchy Bob]

That sounds a bit suspicious as the metre wasn't defined until 1793.

Thank you for your comments, and I believe you are correct. It does sound suspicious! The information in the Dixie catalog was assembled by Turner Kirkland. I can tell you that the Springfield internal lock screws are not of any current standard American size. I recently bought a metric Screw Checker and will test Mr. Kirkland's hypothesis at the first opportunity.

Notchy Bob

 

[Canute Rex]

Thanks for all the responses. It's a 1/4" diameter thread. I looked in TOW but I didn't see a 1/4 x 26. I've read that this was fairly standard in the mid 19th century.