Item Type: Square Hole Mortiser Drill Bit Material: Bearing Steel Drill Bit Diameter: Approx. 8mm / 0.31in Usage: Suitable for wood products such as density board, medium fibre board, particleboard, wood, etc. Suitable for square hole drilling machine, square tenon machine. 1Drill Flute: U shape chip remove slot enables clean drilling, which will largely improve your working efficiency. 2Higher Safety: The stress on the bit sleeve edge is in a plane, effectively protecting the bit from bursting. 3Wide in Match: Universal 5/16in round shank ensures stable clamping on both square hole drill and tenon machine. 4Broad Utility: Suitable for various wood materials such as density board, MDF, particle board, very practical. 5Good Material: Using premium bearing steel with high hardness, not easy to deform and durable for long term use.1 x SquareHole Mortiser Drill Bit