Bosch 2608900570 HEX-9 Multi Construction Drill Bit 4mm The Bosch 2608900570 HEX-9 drill bit has a 4mm diameter and is ideal for drilling practically all materials including concrete, brick, wood, plastic and more. The 1/4" shank provides optimum power output whilst the carbide centering tip ensures a precise start up and good control. This model is extremely durable thanks to its diamond ground cutting edges. Features: Suitable for drilling practically all materials including concrete, brick, wood, plastic, thin sheet metals, ceramic and tile 1/4" hex shank for optimum power transfer The carbide centering tip ensures a precise start up and good control when drilling Diamond-ground cutting edges for wear-resistant Specification: Pack Qty: 1 Diameter: 4mm Working length: 45mm Overall length: 90mm