MAKITA 8406 240v Diamond core drill – 13mm keyed chuck. Has the following features. Max core diameter: 152mm. An introduction to diamond core drills. Are often used by plumbers & heating engineers to drill through concrete & brickwork. Diamond core drills are mains powered due to heavy nature of the work these tools can undertake. To choose between diamond core drills. The key consideration when selecting between diamond core drills is the maximum drilling diameter required. Additionally, if you want to use the drill for applications other than just diamond core drilling, you will need one with a keyed chuck. An attachment is used to enable diamond core drilling. Due to the 13mm keyed chuck, these tools can also drill metal, plastic & wood providing the drill bit has a 13mm or smaller diameter shank to fit the chuck. The drill bit is tightened into the chuck using a key supplied. To make sure you’ve got the right diamond core drill – 13mm keyed chuck. There is often a choice between single or 2 speed gears. Most diamond core drills have a variable speed function.