Carbon graphite seal rings or faces are typically molded to a rough shape before being impregnated with resin or metal binder Carbon fill with metal/antimony carbon seal faces or rings are especially subject to corrosion but a suitable resin filled carbon seal faces or rings can usually be found for most services. Carbon graphite seal faces or rings are not recommended for aqua regia, oleum or perchloric acid. Resin-impregnated carbon seal rings or faces  in common use are attacked by lithium hydroxide, potassium hydroxide, sodium metophosphate, anhydrous ammonia, sodium diphosphate and sodium cyanide. A metal filled carbon graphite seal face or ring is generally better in strength, hardness and modulus of elasticity than resin filled carbon graphite seal faces or rings.