M4 Machine Screws Slotted Countersunk Brass DIN 963

M4 Machine Screws Slotted Countersunk Brass DIN 963 M4, Machine Screws, Slotted. What is a machine screw?. A machine screw is a fastening device similar to a bolt but having a pozidrive or slotted head which allows it to be turned with a screwdriver.