Glock has been making components and complete pistols in the US for some time now and Austrian production is not being phased out.
Tenifer is simply a trade name for a chemical process that is done in the US under the trade name Melonite. Only a materials engineer can intelligently explain the difference so that shouldn't be an issue from a consumer's standpoint. Either process is just a surface treatment to the metal - an applied finish (like Cerakote) is what gives the slide its finished appearance.
The quality of the US made pistols is indiscernible in appearance or performance.
Cerakote is a sprayed on coating process that�s just a good, strong coating. Tenifer/Melonite is a salt bath ferric nitrocarburizing process which is sort of a case hardening. The process involves heat typically under 1,000 degrees where the nitrocarburizing imbeds into the base metal. Then the part is immersed in an oxidizing bath which gives it its black appearance; much like a matte bluing or black Parkerizing. When it�s done, the part has a surface hardness that is VERY hard, and because it�s so hard, it resists wear exceptionally well.
Tenifer is not different from melonite, and the whole thing about the cyanide and the EPA is just internet gossip. Both Tenifer and Melonite are the same process, and both use cyanide.
http://www.met-sol.com/assets/Industry/MSI_FNC_Brochure.pdf
