Threading a punch tube

[chuck123wapati]

10 hours ago, TomE said:

Good tip!  I'll try the potato for the replacement tube that has the same problem with shallow threads.

darn right it is, will work fine that way.

[MikeRock]

Anything will do, apple, orange, you get the idea.

If you want to have fun with a potato, rub the cut surface on American paper money.  Or use spray starch.  The little pen they use in stores to detect counterfeit money is nothing more than an iodine pen.  US paper money does not contain starch, so the iodine won't react.  If there is starch anywhere the iodine reacts with it and turns almost black.   Got this from high school chemistry class.......a LONG time ago.   I daydreamed of slyly spraying cash registers with spray starch when in Vegas once.  It would cause a bloody panic!!   Enjoy! 

God bless

[bruce johnson]

On 12/25/2021 at 9:44 AM, TomE said:

Thanks, Bruce.  Good information.  My spring punch is about 5-6 years old, and the 00 replacement tube fit whereas the 0 tube in the same order had shallow threads.  Following advice from @chuck123wapati I annealed the tube, cut in the threads with a 5/16-24 die, hardened and tempered the tube, then cleaned up the cutting edge and polished it.  I had to punch some oiled leather to clean out the exit hole and now I have a working punch.  Thanks to everyone for their input.  It is a privilege to connect with so many experienced leatherworkers here. 

I was more comparing the threads on a 100 year plus old Newark marked single tube punch vs the Harrisons. Still when I clean one up and sharpen or replace the punch tubes I run a tap through the frame to clean the threads. I screw my punch tubes in to bottom out the tube threads so they wont twist while I am punching also. 

[TomE]

6 minutes ago, bruce johnson said:

I screw my punch tubes in to bottom out the tube threads so they wont twist while I am punching also. 

I had to run the die into the collar of the tube to finish the threads lower on the tube.  By trial and error I found how far to cut threads so they bottom out with the tube squarely contacting the punch anvil.  The tube is firmly seated on the finished threads at this position even though some partial threads are showing.

[bruce johnson]

Gotcha, I haven't run into that much thread showing to meet the anvil.  Just another curiosity question here. Is the frame marked on the other side or have the Osborne maker and size number been ground off. I haven't had that weren't marked on this side that I remember.

[TomE]

Here is the mark. 

[bruce johnson]

Thanks! Have heard about the etched marking but hadn't seen one yet. Appreciate the picture. I have a set of new ones a customer is sending for me to sharpen the tubes and number stamp the top and side of the frame. I know what I'm getting now.