bolt heat treat

[swordfish]

I am new here. I am building a micro and standard uzi taking great pains to make sure all regs are adhered to. I have to convert one bolt to semi auto. I have a heat treat oven so annealing is no problem. It will also heat treat and temper the bolt after the machining process. I can find nothing on the web about reheat treating a uzi bolt. I would like to know how other people have done this so as not to reinvent the wheel. Dozens of references about annealing but no info after the machining process. Please help

 

[sniperdoc]

Unless you also have access to at least a milling machine and top quality drill press or lathe, and have a good bit of gunsmithing experience, I would recommend either buying a semi auto bolt or sending it to a specialist.
The heating isn't the hard part, it's the metal work. You could do it with a hand drill and a file, but it would take a while!

 

[swordfish]

bolt heat treat

Have all the tools , mill lathe and a good bit of experience. I have annealed and reharden bolts but never an uzi. Not knowing what steel a uzi bolt is made of I would like to know what other builders have done and worked.

 

[X-Ray Zulu]

I did a little search but nothing official... I would bet the suppliers used 4130 and processed accordingly. Aftermarket sellers today tout 4140 in use today. After annealing the machining difficulty scale is only 5% difference.
https://www.capitalsteel.net/news/blog/4130-vs-4140-steel-comparison
Hope this give a little help. Cheers.

 

[dgleavitt]

Is it accurate to say the only reason to harden an uzi bolt is wear resistance? Making metal harder doesn't improve its tensile strength, right?