A lesson in metal tempering
 

John, I mean the reciever (bbl extension), the "handle part" is the frame. Carbon steel is annealed (removing hardness) at around 1000-1400 deg, depending on the amount of Carbon in the steel. This temperature is usually attained at a dark red or "cherry red" color. It is hardened by heating to 1500-2000 and "quenching", or cooling rapidly by dipping into some type of oil or brine water, depending on the type of steel. After hardening it is very brittle, and must be "drawn" to remove the brittleness. This is usually done by bringing the piece up to a lower temp slowly and letting air cool slowly. The drawing temp can be anywhere from 300 to 800 degerees. If you are making a spring for instance, the drawing temp is around 800 deg. For other parts such as Luger small parts, it is a lower temp (which gives the "strawed parts" their distinctive color). The "fire blue" color is attained at a temp of around 550-600 deg. For a part that has already been tempered and drawn, reheating to this temperature will not effect the hardness or toughness of the metal because this was probably close to the "drawing" temperature anyway.

Addendum
 

Some Luger small parts are "fire blued" rather than "strawed" because they were drawn at a higher temp. The toggle pins and trigger bar spring are two that come to mind. If this temp/color would effect the hardness of the steel, they surely wouldn't have heated the toggle pins to this temp.

Great lesson Hugh...This info would be good for FAQ! (EOM)
 

Re: Great lesson Hugh...This info would be good for FAQ!
 

Extractor, toggle & receiver connecting pin and grip screws are heat treated blue according to the DWM and early Mauser tables. I always thought that this is what we call annealed. Patrick

Re: Heat Treating-Patrick
 

You are correct, "annealing" and "drawing" are the same thing. It is the process whereby the "hardness" of the piece is retained, but the "brittleness" is reduced.

Re: Re: Heat Treating-Patrick
 

I hate to enter anothers correspondence but in this case I must clarify an error in statement. annealing removes all heattreatment leaving the material in its softest and weakest state. and iusually used after welding snd some machining processes to allow the material to be relieved of unwanted internal stresses.

Drawing is the final step in controlling the Hardness and ductility of a material and usually follows heating and quenching the material to its hardest and most brittle state.

the higher the Drawing temprature the less brittle the material becomes. also the weaker the material becomes.

and if carried to the extreme the metal is annealed and soft

Misunderstanding these things have resulted in failure of firearm parts with pain suffering and even death.

viggogdereng@aol.com

Re: HOLY SMOKES...!!! (and I'm looking for parts)
 

John D, I do have all of the PO8 parts that you requested including the #15 Main axel. Suggest that you email me for details. Tom

Thanks Tom..!!
 

You should see an email from me sent a day or too ago..?? I'll send another in a moment - my e-mail address is:


johnd@rennlist.com


Thanks again!!!