$158.$ Carbide tipped cutting tools are manufactured by powder metallurgy techniques and have a composition of

$90\%$ tungsten carbide and $10\%$ cobalt

$70\%$ aluminium oxide & $30\%$ silica

$30\%$ nickel, $15\%$ chromium & $55\%$ tungsten

$65\%$ tungsten & $35\%$ zirconium