P-412 tape by Nitto Denko is a 3.8 Mil extruded PTFE ribbon dope thread sealant tape. It has a higher density than most thread sealants. It is non-toxic, non-hardening and permanently self lubricating. - Completely inert to virtually all known acids, alkalies and caustics. High density, high specific gravity non-expanding. Prevents corrosion when threaded fittings of dissimilar metals are joined.