Claven 2 they are 8620
Originally posted by Different:
"I was given incorrect information from a credible source back in 2004.
For the bazillionth time, Chinese receivers are NOT made from high chromium series steel. Repeat, they are not made from 5100 series or 52100 steel. Ignore the 2004 article, please.
Chinese receivers are made from equivalent AISI 8620 steel. Smith Enterprise, Inc. examined and tested the first Poly Technologies receivers imported into the United States including some of the raw forgings. I have seen Polaroid photos of these first receivers and forgings at Smith Enterprise. Smith Enterprise, Inc., Keng's Firearms Specialty and Poly Technologies met twice for several days back in the 1980s to discuss receiver manufacturing.
If that is not good enough, Karl Maunz also had the Chinese receiver independently tested in the late 1980s while he was living in Georgia. Same result, steel that is equivalent to AISI 8620."
Post #148
http://www.canadiangunnutz.com/forum/showthread.php?t=447915&page=15