ZIRCAR Ceramics’ Refractory Hardboard Type BM products are a range of structural insulation boards that combine calcium silicate cements with inorganic binders and reinforcing fillers. BM boards are designed to deliver low thermal conductivity and high strength to a wide variety of thermo-mechanical insulation applications. BM products exhibit high dielectric strength, very good thermal shock resistance and when coated with BN are non-wetting to molten non-ferrous metals. BM products are manufactured in sheet form on large filter bed presses, autoclaved to maximum strength, then sanded and milled to final dimensions.Uniform in density and structure, Type BM Refractory Hardboards are readily cut, drilled and assembled using conventional carbide tooling. Type BM is available in three varieties.