Extractor Rod Knurling

dangt

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Two S&Ws I purchased in the last year were in decent shooter shape but both had damaged knurling on the extractor rod. Both guns had right hand threads on the rods and I suppose they loosened in use and someone used pliers to tighten 'em up again. Both were unsightly since the guns overall were in at least very good condition. I could not find rods because of the right hand threads so attempted to repair the damaged knurling by passing a correct sized knurl over the existing area. I did not want to remove metal, reducing diameter and knurl again afresh. I feared that would be too noticeable. After measuring the lines per inch on as many rods as I could stand, I searched for knurls that came the closest, since I intended to mate up to the existing pattern. It seemed to work fine but I did not take any pics of the three ( a third test rod from my discard stash ) was done first.

Mating up to what knurling remained and knurling somewhat deeper, or at least with some added pressure, restored the knurling adequately for my eyes. I have another gun, a later 28-2 that also has damaged knurling and I have taken pics of the different stages. The first pics are from different sides of the rod showing not only plier damage but also double-track of one of the original knurls.







Dan T.
 
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I've got some pics of the rod after reknurling or chasing the damaged knurling. There is still some damage showing but the double-tracking is almost gone. Doing this removes all existing bluing in the knurled area. When finished, I intend to rust blue without removing what is left of the original bluing on the rest of the rod. This will take several days and I'll post more pics then.

Maybe somebody like WAS1911 or some other machinist might suggest some other hints.





Some remaining damage can still be seen in the last pic but I expect it to all but disappear after being blued and looked at without magnification.

Dan T.
 
That looks nice. After bluing, I doubt anyone would pick it out as re-done unless you pointed it out.

On really badly damaged ones, I've turned the bad knurling right off plus a tiny amt. Then put a sleeve onto the end w/ red locktite. Turn to the right dia and knurl once again.
Rust blue when done.
It's a bit more work but sometimes the damage is so bad there's no other way.
 
2152hq,

That's exactly what I intended if I was not satisfied with the results of the re-knurling over existing damage. I knew I risked work hardening the steel and worried about what I might be doing to the inside diameter. On the four rods I worked on, no problem and they turned out well. Bluing when finished seem to hide, rather accentuate, small defects. The rod pictured above looked pretty awful and the poor 28-2 needs more help than just the knurling on the rod.

Dan T.
 
If you're careful (and have the time) you can restore most rods using a fine cut Swiss triangular needle file to re-cut each groove and re-point the tops.
 
Thanks for all the "encouragement." This was not really a matter of taking a lot of skill. It was using patience to count the knurls of several rods, calculate the lines per inch needed and then search for a set of knurls that matched as closely as possible, since I was matching to existing knurling not forming new. I've posted more pics than needed, I think, but am fascinated with my new camera's capacity.

These are final shots of the blued repaired rod:




 
That's actually quite amazing work. Most people simply replace the rod. I truly respect a man who can salvage a damaged part with hand work like you did. Very nice.
 
Someone told me a way to do a knurling job that if you have a lathe sounds like it might work. If you have an older smith with the knurling buggered up and you can't find the right length rod, find any size and turn your old knurling down. Now cut off the good knurling and carefully chuck it in the lathe. You have to bore it out to the same size as you turned the old rod down. Now epoxy it on.
 
Dangt,
You do very good work! You probably could make some good money doing that for other people!
Dick
 
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