SBX™ HT is a Hot Black Oxide conversion coating for ferrous metals that blackens a wide range of carbon steels, alloy steels, and hardened tool steels including cast iron, malleable iron, and wrought iron. This process produces a true black oxide iron magnetite (Fe3O4) finish on metal surface. It meets MIL-DTL-13924 Class 1 specifications. It is a unique powder blend of alkali salt, oxidizing agent mixtures, with corrosion inhibitors, accelerators, penetrants, catalysts, appearance enhancers to darken the surface, light reduction reflection, uniform dispersant, stabilizers, buffering agent with fluxing properties, and a multifunctional source of boron. The end result; the process doesn't add or remove metal from the substrate; instead, it converts the surface layer into magnetite. Note: SBXTM HT will not blacken stainless steel. For stainless steel see our SSBXTM HT product.
The resulting thin layer provides several advantages, including greater corrosion protection and wear resistance maintaining high tolerance requirements, attractive smooth appearance, and doesn't significantly increase the overall dimensions of the parts since the black oxide layer is about 1µm thick. This is a distinctive advantage for parts such as gauges, cams, bolts, precision machined surfaces or other close-tolerance parts since dimensional change is not an issue with black oxide finish. The black oxide finish reduces light glare on moving tools and machine parts which, reduces eye fatigue making operations safter. For further information see TDS.