AK47 Part 3 Receiver Heat Treat and Rockwell Hardness Test скачать в хорошем качестве

AK47 Part 3 Receiver Heat Treat and Rockwell Hardness Test

Full Heat Treat and Rockwell Hardness Test of an AK47/74 Receiver: Edit 6/24/15 (THE POLISH BLANKS ARE NOT 8620) Edit: 6/24/15 I have had problems with misidentification of 4130 and what I thought was 8620. The Polish blanks are not 8620. They are steel 50 which is more like our 1050 steel, and now that has been cleared up. I can now successfully heat treat the flats and blanks. See "Heat Treat Problems" to get the low down. This 80% Polish receiver blank is made from 8620 steel and not 4130 like all the other receivers I've gotten from AK Builder. This will be a learning process for me. One thing I forgot to mention is that all bent metals must be stress relieved. I was in a hurry and did not film or even talk about stress relieving the receiver. I also did not show the draw and Rockwell of the finished receiver. This is because the receiver that you see in the video was not stress relieved because I was in a hurry and forgot to do it. Oops! that was a no-no, The receiver warped and cracked from the mag well to the trigger slot. I did not notice until after I had done the draw process. Good thing I already had another receiver. Well after the learning process, I found out that if I use the tried and true method I have used for the 4130 receivers it works better than what I found on the web to heat treat an 8620 receiver. 4130 Receiver heat treat (also for the 8620) process that works best for me. Place the receiver (without the rails welded in) on the top rails. Then bring the oven up to 750, hold for 2 hours. Then ramp up the temp to 1600 but do not hold at that temp. Remove it quickly and dunk it in quenching oil. After the oven has cooled, place the receiver back in the oven (upside down on the top rails) and draw it back at 750, hold for 45 minutes, then let air cool. The times and temp are from "TheDarkKnightBuilds". I recommend you go check out his videos.