TOW Nipples Don't Fit

[tomykay12]

So, I ordered a set of ss nipples for my older Pietta 1858. They said PIR-S, 6x.75 are the correct ones. Well, they are close, but don't thread in properly. They start, but tighten up progressively and don't seem to seat. Obviously a thread that is close but not quite right. Guess these will be going back, or find a tap and chase the threads. This is a never fired gun. Wonder if Pietta used a different thread 15 years ago. tk

 

[44 Dave]

I had a similar problem, current nipples called for 12/26 mine needed 6/.75
Might be 12/28
Could check new along side old ones or go to a good hardware store and buy 1 12/28 screw and see if it fits.

 

[tomykay12]

Yep; my issue seems opposite yours. Too close to eyeball. I've turned a few wrenches, and these are not the right thread. Close, but not a Lewdinski. tk

 

[amandabab]

My TOE pir-s 6-.75 fit my pietta perfectly.

on the 1858, they don't thread in parallel to the bore axis. they angle out several degrees. trying to thread them in straight will cross thread them or make them seem like they are binding.

 

[mykeal]

My Pietta c&b revolvers run from 1977 to 2001 and all take 6X0.75mm threaded nipples.

The inch unit values for 6X0.75mm threads are 0.236" MD and 33.9 TPI; there's really no SAE equivalent that's close.

I think you need to chase the threads in the cylinder.

 

[tomykay12]

Yep, I'm thinking that as well. There is a really cool hardware store here, Marshalls, that has lots of unusual stuff and they probably have that tap. The threads look very clean, and the nipples came right out. Interesting; the threads on the old nipples are quite sharp and defined, while the TOW nipples look a little blunt and sort of rounded. Could just be a function of the material. Gotta be the right nips, but I will call them and ask anyway. Oh yes, I detected the angle as i removed the old nipples. I have turned a few wrenches, lol. Even the issues with these things are fun, tk

 

[tomykay12]

tap ordered......waiting, waiting, tk

 

[tomykay12]

Well, the tap came from China in record time. I chased the threads in the Pietta cylinder, and more was cut than I guessed would be.... Bottom line is the TOW nipples now thread in correctly. I don't know what thread this 15-18 yr old Pietta had, but it was definitely NOT M6x.75 unless they were full of bluing rust residue. Who knows. Old Chinese brothel saying "any happy ending a good ending" applies here, tk

 

[44 Dave]

Glad you got them to match up with current manufacture. Are the TOW nipples the right length?

 

[tomykay12]

Good question; I must rely here on TOW expertise. It may be a little bit before testing real time. They were emphatic on the phone regarding nipple correctness... We will see, tk