The centre drill for the Multi Material hole saw is made of high-speed steel and is ground for long-lasting performance. The centre drill bit for the hole saw for brick and soft tiles has a tungsten carbide tip for effective drilling through building materials such as brick, soft tiles, cement board and plasterboard. Effective guidance and prevents 'walking' of the hole saw Hexagonal shank for strong connection and maximum torque transfer in chucks with three chucks and 1/4" hexagonal toolholders