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Posted: 6/6/2005 3:13:19 PM EDT
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Hi all, Just built two receivers at the OK build party, and I need to know about ejector hardness. We heated the tip of the ejector up red hot and quenched it in water. I'm concerned that it is brittle hard and might snap off. So I'm thinking of tempering it using Tempilstiks and a torch. So my question is, do I even need to do this? And second, what temperature should I temper it to? Thanks Dave |
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Heat Treatment Heating at 1600 F followed by an oil quench will harden the 4130 alloy. For best results a normalizing pre-hardening heat treatment may be used at 1650 to 1700 F followed by the 1600 F soak and oil quench. Tempering Tempering is done to restore some of the ductility that may be lost after the hardening heat treatment and quench. Alloy 4130 is tempered at between 750 F and 1050 F, depending upon the strength level desired. Properties of Alloy Steels 4130 |
| I heat each pivot pin hole and the ejector tip to red orange then quench in water.I polish each hardened area to bare silver with 300 grit wet/dry sandpaper then I heat each spot till fire blued.I've not had a problem with any of my rifles after over 1000 rounds,no deformation of the ejector or egging of the pin holes. I use a small Burnz O Matic MAP/OXY torch from Home Depo which puts out a small fine point flame so its way more precise and much faster than a plumbers soldering torch. |
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Dave, I just went through 120 rounds on one of the receivers heat treated with the oxy-acetylene torch. No deformation at all on the ejector tip! The ejector is definitely HARD as a file would barely touch it when I was fitting in the bolt carrier/bolt. The rest of the rail is not that hard and has some "flex". I really don't believe the ejector is brittle as well as hard considering all that was heated was the tip of the ejector. Dan |
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