Tennifer is a salt-nitride process used to harden the surface of steel (.69RC) and to provide superiour corrossion resistance.
Older Glock slides were then finished with a type of parkerizing. The newer (G3) ones have some kind of shiny teflon finish. The finish is for cosmetic reasons and it will burnish, at least the parkerized ones will. Haven't had the teflon finished one long enough to know how it will hold up.
The barrel has some kind of finish on the outside, looks like teflon, but the inside of the barrel is just tennifer treated steel. Tennifer treated steel is a dull dark gray in color.
Look at the feed ramp of a glock and the metal inserts in the frame. That is what tennifer treated steel looks like.
Tennifer process:
4. Nitriding and Nitrocarburising
In nitriding, nitrogen is diffused into the surface of steel components by heating them to about 520oC in an atmosphere of ammonia or exposing them to a low pressure nitrogen + hydrogen atmosphere while they are subjected to a glow discharge. To obtain a high surface hardness (above 750 HV) elements that form hard nitrides, eg Al, Cr, Mo, V, must be present in the steel.
Due to the lower temperature than that used for carburising, the process times are much longer (20 + hours) and this factor combined with the fact that there is no quench means that danger of distortion is greatly reduced.
Nitrocarburising is a variation on nitriding, normally carried out between 570 and 585oC in either a molten salt bath or gaseous atmosphere. A treatment time of 90 - 120 minutes gives a shallow layer, about 20 micro m, and although this is not particularly hard, it provides excellent wear and fatigue resistance.
There are a number of proprietary processes: Tufftride, Tennifer, Nitrotec. In some variations sulphides are added to the salt bath, giving even better wear resistance. Two processes are Sulfinuz and Sursulf.
