RS PRO Counterbore M12, 100 mm x 20mm Cut Diameter, 1 Piece - 132031

HSS Individual Counterbores. Counterbores for cutting holes where a capscrew or fastener is required to sit flush or even below the level of the workpiece. Thread size is the size of the screw thread to sit within the hole and cutting diameter shows the size that will be cut for both the capscrew and head.