doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com How difficult is tu turn a hinge pin in a Sauer.

What we need is a real how-to thread on fixing this problem, from several perspectives IMHO

Plasma spray welding is a low temperature build up process- the heat input into the metal is low, prevents distortion-- most hinge pins are a free machining grade of steel in US made weapons- AISI 1018- and then oil hardened to a Rockwell C scale in the 56-62 range--As your shotgun was made in Germany, the steel will most likely be Krupp or Siemens "Hardstahl" with a higher nickel and chromium content- the Germans and Austrians built their firearms to last for centuries to come- and their metallurgy is unsurpassed- IMO-- But heat input from the TIG (tungsten inert gas) process is difficult to control on a radiused area- and the heat 'chases itself in a manner similar to a Mobius strip configuration- Plasma does not allow this to happen- I would suggest Kirk Merrington in Kerrville, TX. You are indeed fortunate to have such a fine "schrottenflinte"- the Spanish guns for years suffered from an ill-deserved reputation as having poor metallurgy- guess "Cactus JacK" O'Connor forgot about the great swords made in Toledo, Spain- no es verdad???

A piece of 1018 steel will obtain virtually no hardness from a heating & oil quenching. Carbon steel does not really begin to respond to heat treating until around a 1030 steeel & at this carbon level a water quench would be normal.
1018 steel is subject to being "Surface" hardened through Carborizing (AKA Case Hardening) but is not a through hardening steel.

Jose,

I suggest temporarily using the strip of beer can aluminmum shim. It won't cost you anything and it'll give you a chance to try the gun for a while to help you decide if you really want to keep it. If after shooting the gun for awhile and you decide that it is a gun you'd like to keep, then fix the hinge pin.

I've learned to do that with any gun I buy that's a little loose. No use spending the money on a gun I don't want to keep.

Steve

Just going by what I read in the Brophy book on LC Smith plans and Specifications (Brownells 1981) I was surprised they showed AISI 1018-1020 mild steel for the hinge pin, but did indicate carburizing and an oil bath quench--You are correct, all steels need a minimum of 30 points of carbon content or more to take heat treatment, no matter the quenching medium used and the resultant Rockwell or DPH reading desired-- and I should also mention that in tool steels (way different in analysis that 1018 steel) there are three basic types: Oil hardening, Water hardening and Air hardening. Carpenter TK and P21-lusterdie were several I used to be familiar with-- 'back in the day'!!!

Jose,
It his been a long time sense I have shimmed a barrel hook. At that time I didn't have the money to send it to a gunsmith.
I bought a blade feeler gauge, used it to measure the distance between the breech face and the barrel face. I then cut the feeler blade, 0.004", and made a shim and placed it in the curve of the hook. I used the gun with the shim in place for awhile. At a later date I took the shim out, softened it with a torch, tinned it with solder, I also tinned the curve of the hook with solder. I then clamped aluminum dowel of the correct radius to hold it in place and soldered it in place, when it cooled I trimmed it with a knife. It worked for me.
Good Luck