<unk>  (TaC) is an extremely hard refractory ceramic material, commercially used in tool bits for cutting tools. The hardness even exceeds that of diamond .  It is a heavy, brown powder usually processed by sintering, and an important cermet material. It is sometimes used as a fine-crystalline additive to tungsten<unk>  alloys.<unk>  has the distinction of being the stoichiometric binary compound with the highest known melting point, at 4150 K (3880°C) .  The substoichiometric compound TaC0.89 has a higher melting point, near 4270 K (4000°C).
When used as a mould coating, it produces a low friction surface.<unk> -graphite composite material, developed in Los Alamos National Laboratory, is one of the hardest materials ever synthesized.
Dusts from grinding can be flammable.
Substances to avoid are: flammable gases (dust may form explosive mixtures with gases)
Tantalum carbide
Chromium carbide
Psyllium
Cadmium oxide
Carbon black
Arsenic tribromide
Cadmium sulfide
Coal tar