The friction surfaces (R) are after-treated by way of carboring, carbonitriding, case hardening, gas nitriding, oxide nitriding, gas nitro carburizing, plasma nitriding, plasma oxidizing, borating, plasma carborating or plasma borating.

The surfaces of the die, including surfaces inside the extrusion holes, are hardened by gas nitriding or plasma nitriding.

Parts may be vacuum hardened and then be given a gas nitriding treatment.

AMS 2759/6: Gas Nitriding and Heat Treatment of Low Alloy Steel Parts

The other material of the slide pairing is an iron-containing material, the slide surfaces of which have a nitrocarburising layer or a gas nitriding layer.