With all the choices on the market, finding a drill bit that is right for you can be a nightmare. This article will hopefully shed a little light on the subject. Steel and carbide steel are similar except that carbide steel is harder and more brittle that standard steel. Carbide steel is created by heating steel to glowing red and then rapidly cooling it. This aligns the carbon molecules of the metal.
Heat treating the steel makes it stronger but more brittle.
This is why standard carbide bits will dull quickly and break off inside your repair. They also can deposit small metal particles which can contaminate the repair. Tungsten carbide steel is a tungsten alloy added to the heat treated steel. Tungsten carbide steel is also very hard but not brittle and won t break apart during drilling. Diamond burs are made by bonding diamond dust to a steel shaft.