Drives
Slotted screws are driven with a straight blade screwdriver that fits the slotted drive; this is the oldest and simplest drive form. The disadvantage of this drive is that it can twist out under torque especially if the screw slot or driver tip becomes worn. Commonly found on tapered thread woodscrews and parallel thread machine screws in domestic applications or where field retightening or removal may be required. It has many applications, but is not suitable for power driver use.
BSW Whitworth Slotted Countersunk Head Machine Screw Grade-4.8 BS450
Inch Slotted Raised Countersunk Head Self Tapping Screw AB Case Hardened Steel BS4174
Inch Slotted Raised Countersunk Head Self Tapping Screw B Case Hardened Steel BS4174
Inch Slotted Pan Head Self Tapping Screw AB Case Hardened Steel BS4174