DURO 13mm x 320mm A-Taper Drill Bit For Diamond CoresDURO 13mm x 320mm A-Taper Drill Bit For Diamond Cores have been precision machined from a premium grade metal enabling you to mark and drill the points to want to drill into with a larger core from the DURO range. This drill bit will help you ease the progression of the core bit into resistant material. Use Me For:Hard York stoneLondon brickGeneral house brickHandmade bricksFacing bricksLightweight concrete blockBreeze blockFeatures:Long life Precision machinedPremium metalSpecification:Size: 13 x 250mmFitting: 3 Jaw drill