Temper of Mainspring Guide?
 

I have a question for all the experts here:

I am in the process of making a mainspring guide for my baby Luger.

Instead of forming a new hook on the end by hand I have elected to cut a section out of the guide and get it micro tig welded back together.

I dropped it off at my welder tonight and was wondering if I should temper it when he is finished?

If so how exactally? I have tempered small parts in the past but want to make sure I get this right.

Here is a photo of the guide before welding. I believe he is going to grind the edges of the cut to get a full pen weld.

Thanks to all who respond!

I'd polish it and then draw to a bright blue; which should remove any "strain" left from the welding.

Depending on how he welds it, it may not show but 1/4" of "heating" on either side of the weld.

Please post a picture when it is returned before you do anything to it.

Thanks Don,
I will post an after weld photo as you suggested.
After heating the part to a bright blue should I quench it in oil or just let it cool naturally?

It's interesting the way different minds work. :)

Just for my own curiosity, why did you decide to cut & weld an old part rather than make a new short guide from drill rod???

I can see going either way... by cutting and welding, you avoid the work necessary to form the hook...
the amount of work to dress the weld seems to be less than the precision needed to form the hook properly.

Just my $0.02 :cheers:

Well, I don't know how I could make this part out of a drill rod, but you have a much more advanced skill-set than me so i'm sure it would be simple for you to whip one up.

The whole idea with this new part is to have a better hook on the end than one formed by hand. GT helped me out by supplying a NOS Mauser or Swiss part that has more of a hook on the end when compared to an original part.

All in all this project should only cost me 20 bucks for the weld and a couple hours of my time.

Main spring strut / guide!
 

Hi to all, The guide Miles chose to modify is a pretty neat and unique design? It has more full circle bearing area on the recoil lever end and I have never seen such a part on a war time Luger or before? I am assuming it is new Mauser parabellum or perhaps Swiss, as those are the outfits that could, would, most likely make something like that? Does anyone know for sure the origin?.. I would like to know myself... best to all, til...lat'r....GT:cheers:

Here is a better photo of the "hook" end.

I notice a "rib" on this guide, looks almost like it was cast?

Ron,

I noticed that as well. I was wondering if it is perhaps a metal injection molded part?

In any case, my welder just called and the part has been welded. I am headed to his house after work and will post a photo of the result.

Metal injection is probably a much better description than cast.
Ron

Here is the part post welding.
The length is right on the money.
The one the gun came with was 51.77 mm and this one is exactly 51.77 mm.

Smooth up the weld and polish it, draw to blue and let air cool. No quench.

I'm not sure how well the "sintered" parts weld- the line indicates a "cast, injected, sintered" part- made in a mold.

Rich would have made the part from a drill rod using his lathe and milling machine!

It works!!!
Just fired three rounds with no issue.
Thanks for all of your help, especially GT and Don.

Fire it another 100 rounds to break it in!

Congrats on the successful function test of your "baby" :thumbup: