Boron carbide (chemical formula approximately B4C) is an extremely hard boron–carbon ceramic, and covalent material used in tank armor, bulletproof vests, engine sabotage powders,
B 4080 (OTTO) Boron carbide, 1-10 μm, 99%+ Cas 12069-32-8 - used in refractory applications due to its high melting point and thermal stability.