High Speed Steel Good balance of cost and durability. Maintains hardness (temper) at high speeds
Hart Bur (Bearing Cutter)
Available in 70˚ and 45˚ profiles, this is the most commonly used bur for stone setting. Its shape makes it perfect for cutting seats in prongs and for channel and flush settings. Hart burs can also be used for scoring lines or as an alternative to flywheels for bright-cutting.