GTA
General Discussion To Gateway To Airguns => The Shop => : gunsup0331 December 09, 2008, 02:02:56 PM
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Going to be cutting a new sear out of mild steel in the next few days. I need some options on hardening the contact surfaces or the whole piece itself. My oven gets to 500 degrees, I do not have a torch and i dont plan on buying one. I have a grill though and i dont mind playing with fire! thanks guys!
Please be specific!
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Hey Brandon,
Not being sure of my method used, I looked this up on Google. I will note, that there are many grades of steel, and each has a different method and / or temperature to harden it. If you look it up on Google, you will find many other more specific methods, for specific steels.
http://www.youtube.com/watch?v=9tlsq2ESQz0 (http://www.youtube.com/watch?v=9tlsq2ESQz0)
Be careful !
Bill
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mild steel will need carbon introduced into it...this is called case-hardening. 500 degree f. will not get hot enough to do the job. the metal should be heated to 1300 to 1600 degrees (depending on the grade of steel). in the old days a blacksmith would heat the metal cherry red and then bury it in horse poop to introduce carbon. horse poop has carbon in it and smells really good when cooked....1020 hot rolled is a low carbon steel, so you won't have to worry about hardening it because the carbon content is not high enough for hardening without introducing carbon to it. however, 1040 is a carbon steel that responds well to hardening by heat treatment at 1550 to 1650 F followed by water quenching. after cooling, the metal should be tempered (stress relieved or drawing) around 400 degrees for 4 hours and air cooled.
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thanks for the replies so far guys! Looks like i need to A)get a torch and/or B)scrounge up a piece of metal of appropriate dimensions of the right composition
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Brandon, the guy who has the farm near me has lots of horse dung and I am sure he would give you some absolutely freee...:)
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I am pretty sure most of the sears in airguns are mild steel & are not hardened. Not counting springers of course. I have been making knives for about 30yrs. a content of .05 carbon or less realy wont harden. Not counting case harden which is just a cruston the surface. Steel from 1020 to 1070 isnt that easy to find unless you order it. Tool steel A1, O1, D2 you can usually be found local come precision ground & anneled. To give you an idea mild steel is 1010-1020 (.01-.02 % carbon) rebar is 1040-1050 ( .04-.05 carbon) car springs are .08 carbon, files & knives are .08-1.0% carbon anything above 1.0% is very brittle even when tempered. Rule of thumb to harden steel is heat to bright red ( 1500 degrees) quench in water oil or air then reheat to a blue color to temper. Good luck
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Just read my reply added too many 00s. 1010 is .10% carbon 1020 is .20% rebar is 1040-1050 steel .40-.50% car spring are 1080 .80% you get the idea
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yeah, i am on very limited resourced right now as far as tools, etc. are concerned. I know i could take a chunk of car spring, heat it up orange or hotter, bang it into shape on an anvil,and go from there. I got a dremel and a file and i live in an apartment. I got time and ingenuity and thats about it. Once i start workin again I could definitely spring for some toys, but i am on survival mode right now,no joke. I may scrounge up an old file, borrow my dads torch and anneal, shape, harden then temper. Thanks for all the advice so far ppl!
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i don't think you want to be blacksmithing in an apartment. that could be dangerous for you and the other occupants. when you start talking about tempertures above 500 degrees you need to be OUTSIDE or in a SAFE environment.
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of course i wouldnt do that in my apts, lol
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There is an exception to the rule that low carbon steel won't harden. That exception is super quenching. Google super quench and see what you come up with.