TargetTalk

Does anyone know what thread is on the smaller diameter end of the cleaning rod that comes in the box with Pardini SP+HP?

It almost but not quite fits the 40tpi gauge, its OD is around 3mm / 0.12", but it isn't 5/40 nor it is M3/0.5. I can't get any decent fit with neither metric, imperial, nor Whitworth gauges that I have, and I'm on a bit of my wits' end.

Fit with a 5/40 is better than with M3/0.5, but not a real fit - it goes in about a millimetre or so and stops.

I'm looking for an adapter that would let me use standard 8/32 brushes with that rod.

Thank you! :)

Is the pitch finer or coarser than 40TPI?

From my thread chart, could be 5BA or 5-36, or of course some custom thread



It seems like 5-40 is common so its probably that, try turning harder.

https://www.ebay.com.au/itm/271772151029

The OD of the threaded part measures precisely 0.12" / 3.05mm. I can see the "T" ("HOLTZ") in this table that matches, but the rod is very clearly not 55tpi.

The pitch matches 40tpi gauge closely, but not in the shape of the teeth - gauge's teeth don't go into the rod's thread all the way, only fit the top part (which led me to think it may have been Whitworth). But 40G 1/8 Whitworth fits even worse - while it again matches the pitch, teeth on the gauge are much shorter than what's on the rod.

I don't really want to push into the 5/40 adapter because it clearly feels like cross-threading. It actually goes in more than 1mm that I said originally. It goes in about 3-4mm and then tightens up. Also all the original brushes screw on very nicely. One last note is that I can see the difference in ID between the original brushes and the 5/40 adapter, the later being larger.

A bit of a puzzler :(

That really sounds like a regular M3.5 thread. The pitch diameter (which is less than the major diameter, remember!) of an external threaded M3.5 is 3.004-3.089mm, and the thread pitch is 0.6mm, which converts to 42.333tpi. Both these are very close to your observed measurements.

I'll check with the 0.6mm gauge tomorrow, but I'm pretty sure I tried the metric gauges and none fit better than the 40tpi Imperial and Whitworth.

Oh, I know what it is. It's 1/8" x 40 BSW.

In fact, I bet it's this brush, or something very much like it:
https://www.erzinger.ch/produkt/laufreiniger-2/

Greetings,

Curious?

Why have you not contacted Pardini for the information?

Cheers,

Dave

fc60 wrote: ↑Sat Mar 25, 2023 12:12 pm Why have you not contacted Pardini for the information?

Local importer is not very friendly to calls for info.. As for Pardini HQ, I tried sending them questions in the past and never got any answers. :(

Why not just use a rod that fits your brushes?
I’d guess that you already have one

chukeeee wrote: ↑Sat Mar 25, 2023 10:11 pm Why not just use a rod that fits your brushes?
I’d guess that you already have one

I do use a different rod when I'm at home. This one is just foldable / portable and has a its own convenient spot inside the original gun box. I occasionally use it when I'm away. It happens not very often but very handy when it does.

For those of you following this riveting thread at home, I got a reply from the local Pardini importer, quoting verbatim:

"The Pardini cleaning rods are a metric thread as they are made somewhere in the EU."

I'm not sure this helped much. :) Anyway, the next step is this saga is to try if 1/8-40 BSW fits. An appropriate tap is in the mail. If a test hole tapped with it works for the rod, I'll recut the 5/40 thread in the Hoppes 5/40 to 8/32 adapter that I have and call it a day.

-TT- wrote: ↑Sat Mar 25, 2023 11:53 am Oh, I know what it is. It's 1/8" x 40 BSW.

In fact, I bet it's this brush, or something very much like it:
https://www.erzinger.ch/produkt/laufreiniger-2/

Ding-ding-ding! We have a winner! :) It indeed was the 1/8" x 40 BSW. I got a tap, ran it through the Hoppes 5/40 to 8/32 f2f adapter, and now I can use 8/32 brushes with this rod.

Thank you to all who chimed in!

5-40 seems like a common thread for rods and brushes, this thread would have been machine turned, 5-40 and 1/8 BSW are very very close, if the thread gauge had the right pitch but wouldn't fit my guess is its just a slightly malformed 5-40.

The point is I'm right.

JamesH wrote: ↑Mon Apr 03, 2023 4:32 am my guess is its just a slightly malformed 5-40.

Pardini would sell a poor quality accessory!? :) :)

I think it's interesting either way this is an SAE or English thread, from an Italian kit. But perhaps that explains why the threads weren't perfect.

I would guess they outsource it and it just wasn't a good job.

Given that the link to the German bore brush specifically calls out the 1/8" x 40 BSW thread, it's apparently quite intentional, and not a manufacturing mistake. That the lovely thing about standards; there are so many of them... Threads in particular.

Gwhite wrote: ↑Mon Apr 03, 2023 12:12 pm Given that the link to the German bore brush ...

Swiss, actually. They also make a metric thread version (M4x0.5). Shrug.

Thats an archaic thread to be using, when even America has moved on to UNC

Pardini probably got a good deal on old stock...