#10-24 Pan head square drive machine screws. Stainless steel machine screws provide excellent corrosion resistance and are the work horse for modern boatbuilding or exterior woodworking applications. Sold in boxes of 100. Pan head means flat top with smooth rounded sides to provide flat bearing surface under the head to allow for lateral movement (as opposed to a Flat or Oval Head screw that has a countersunk bearing surface that will self-center in the mounting holes). Square drive allows for greater fastening torque to be applied by the driver without worry of fastener head stripping or cam-out occurring. These Stainless Steel Machine Screws are perfect for the marine environment. There are also a million other interior and exterior uses where a stainless fastener will come in handy. Designed for harsh environments.