torque setting for percussion pistol nipples

well I've looked and not seen an answer for this one.

"what is a reasonable torque setting when installing nipples after cleaning?"

there's room for a lot of jokes obviously about this one but would like a serious answer.

10lbs ?

13lbs?

any thoughts appreciated.

camo

Myself, turn until they stop, no force added

Lightly, more like inch pounds.

Phil Coffins said:

Lightly, more like inch pounds.

Click to expand...

yep apologies probably inch pounds.

50 plus years and I finally own a torque screwdriver I use now for rings on unmentionables.

but in reality I've checked damn near any fastener in the household cause I can.

camo

Just tight, I can’t see that torquing them could make any difference .

I have a torque screwdriver for use at work, but don't use it on C&B nipples. But judging from what I'm used to I would *guess* 10-13 inch pounds?
That being said, I agree with Phil above and generally torque to 'snug' with a pinhead sized dot of anti-seize on the threads. Every time. I've never had one shoot loose nor had one seize up using this method. Oh, and get yourself a high quality nipple wrench, not the starter kit junk.

For grade 5 bolts. Nipples probably aren't more than grade 5 (tensile 120,000 PSI min.) strength and the bolster/drum may not even be grade 5.

1/4-28: 8 ft-lbs dry, 6.3 lubed
5/16-24: 19 dry, 14 lubed

Metric 4.8 class (torque in Ft-Lbs)

8mm: 11 dry, 8.5 lubed
10mm: 21 dry, 17 lubed

These are maximum values and I wouldn't apply that torque to any fastener that has less than 3 full threads engaged (4 full turns after the first thread engagement). Nipples will stay in place with lower torque values than these given here. If you feel more comfortable with inch-lbs. you can convert or search online.

Ok, this is truly in my Wheelhouse (house joke as we had a lady visit who is a Captain on a dredge and in her Wheelhouse is true!)

Ok, the most accurate torque is a lubed fastener (that is what we call nuts and bolts). Its purpose is to create a clamping force. A cone is not clamping anything (technically it come to a stop on its shoulder).

Also technically the most accurate setup is a lubed fastener? Why? You are eliminating friction as best you can. Its why head bolts are lubed (back in the day we had a variety of "lubes" the worst being some god awful toxic stuff called Peanut Butter. Anti Seize would be the modern version (mfg for the application will specify what lube).

So the best you can achiever is 20% of the spec. Dry threads are worse. Torque specs and the fastener take that into account so that the over and under still does the job needed.

Now add in, the shoulder has to be perfect (well as close as modern mfg can make it). If you look at a head bolt, you see a tower or recess that is machined. That ensures that a bad surface there does not affect the tolerance.

For a cap screw (yea that is the right term for a hex headed bolt) has a specific surface, so with head bolts the two are made for each other.

Other applications you have to use a washer to ensure you have that good surface. It has to be a quality washer (grade 2 need not apply).

I think you get the idea why there is no torque spec for a Cone. Snug it up by feel and good to go.

Now just for grins I tried as best I could with my setup. It looks to be under 10 inch lbs. Kind of a wild guess as my torque wrench (3/8 type) falls off the map down there.

Mechanics rarely use a torque wrench unless its a very specific fastener that requires it (Headbolts, con rod bolts, main bearing fasteners). I knew one guy who did it on a valve lash lock nut. He had a point there, that is not something you want questioned if there is an issue.

a while back had to make a wrench to fit an odd pocket pistol .31.

this works well on my newer Uberti pocket .31


this will also fit into my torque screwdriver

camo

Don’t over-think it. “Finger tight” with the nipple wrench. Any more than that is overkill and unnecessary.

Terrier said:

Don’t over-think it. “Finger tight” with the nipple wrench. Any more than that is overkill and unnecessary.

Click to expand...

Agreed with that concise summary.

yeah, I know.

just figured since we all geek out about lube, patches, and everything else..........I was surprised that there are no written in stone answers.



camo

Like the compass in my head and the built in torque wrench in my hands.

camoloc said:

well I've looked and not seen an answer for this one.

"what is a reasonable torque setting when installing nipples after cleaning?"

there's room for a lot of jokes obviously about this one but would like a serious answer.

10lbs ?

13lbs?

any thoughts appreciated.

camo

Click to expand...

I have never used a torque wrench on any of mine but if you use the appropriate nipple wrench just snug it down without a lot of force because you will want to remove it at some point and they can sometimes be hard to remove if you tighten them too much. I would hazard to guess somewhere between 10-14 inch pounds would be plenty.

any thing over nipple wrench with fingers tight is stretching the threads in the drum/bolster and leads to thread failure. the metal in the nipple is much harder then the drum/bolster if you don't believe it run a file across a nipple it sings run that same file across the drum/bolster and you will cut a flat. when I repair any of the percussion systems and I weld them up I have to be careful drilling and taping so i don't break the drill or tap and no I don't ever use your local hardware store drills and taps

Starting with CLEAN nipple threads then you apply a SMALL amount anti-seize with a small paint brush or a toothpick. Install the nipple without cross threading it and run it down until it stops then give it no more than an eighth of a turn more or just call it SNUG

P.S. you will NEVER stretch the threads of the nipples without using an extended breaker bar - 6mm diameter X 20 FOOT/POUNDS will stretch the threads - I say this as a mechanical engineer with 45 years of experience with many different types of hardware used in the aero-space industry.

camoloc said:

well I've looked and not seen an answer for this one.

"what is a reasonable torque setting when installing nipples after cleaning?"

there's room for a lot of jokes obviously about this one but would like a serious answer.

10lbs ?

13lbs?

any thoughts appreciated.

camo

Click to expand...

...How many #s of pressure to seat a ball?... How much lube goes on a patch?. Whats the best revolver grease? ...These never get old...but maybe a FAQ list would help...Or not...

There would be pages of dispute over whether the FAQs were valid or not.

After tenthousands of shots for training and competition in my nearly 50 years of competition shooting :

Just hand tight , but the threads always covered with some copper - or zinc paste to avoid "burn't in " threads !

Only my 2ct

Nothing is Writte in Stone: Sometimes it should be!

Click to expand...

Its a fun subject but as noted, none needed and it was and is not designed to need it. Not something you carry in you possible bag!

Torque wrenches did not exist when they designed these guns (yea you could apply it to today's threads and do so but..;..).

As an aside and one I found appalling. One of my guys pointed out two empty holes on a a large fire pump case (4500 gpm x 450 hp engine) , a bit like an air cooled airplane engine that it came with a top that came off (about 1/3 the size of the body so it was substantial). I flipped off they were forcing holes but then I looked and it was, no, no threads in the cap, they are not forcing holes. This hole and that hole are but this one and that one are not.

Phew, its missing two bolts. What the hey? It turned out to assemble fire pump and engine they pulled the two bolts to put lifting eyes in and use as hoist points to move the pump to atach to the skid. Supposed to put the bolts in a bag on the back of the engine (and no idea why they would not replace the bolts then and there) so also werid.

Going through the manaul I could find no torque spec for those bolts. Huh, it is seriously important one, much like head bolts. So I called the factory. Nope, we have no spec. Insult to injury being a fire pump it is certified all to heck and change it at your peril getting into trouble with NFPA (fire pump cert orginaizaion) and the local authorites. Wow.

Factory said, just buy a couple of Grade 5 bolts (not even grade 8!) and good. Well we had 6 pumps and all were missing two bolts of course. Nope, not happening on my watch, you send us the bolts you use, I ain't going to be hung for putting non spec hardware on (each and every component technailly is specified and if you replace something, it has to be the same exact spec item). We had coolant hoses on the engine we were supposed to use the exact mfg and spec if we replaced them (we finally got Corporte Safety to address it and they told everyone to go fly a kite, anything that was a standard item we got their written aproval to replace with equal or better)

I documented we did not have a Torque spec as the factory had none and used a grade 5 lubed spec (anti seize).

If it has a gasket (and this did) you should have a spec (you may not use it as mechanics get a feel and its good enough) but its there in the book. 180 psi pump and the ft lbs of force are in the thousands. No spec. On those when we worked on them we borrowed the 3 ft Torque wrecnh from Vehcile maint and torqued them. No guessing with those kind of forces though the factory was perfecly happy to. It truly can be werid.