How To Make An Elongated Countersunk Hole?

Sizes and availability for Countersunk Head Hexagon Socket Drive Screw in metric measurements, in a range of materials

Nylon Countersunk Slot Nylon Countersunk Thread Screws have a standard flat countersunk head, suited to a range of applications where a threaded hole is

slot drop Trend M4 X 20mm Countersunk Slot Machine Screw - Code WP-SCW04Replacement machine type=CskThread=M4Thread length=20 mmDriver

lock it link slot FFT Machine Screws Countersunk - Slotted - Zinc Plated - DIN 963