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,as well as numerous industrial applications. With a Vickers hardness of >30 GPa, it is one of the hardest known materials, behind cubic boron nitride and diamond.
B 1964 (OTTO) Boron carbide, 100 mesh Cas 12069-32-8 - used as an abrasive in polishing and lapping applications, and also as a loose abrasive in cutting applications such as water jet cutting.