47 Class captive screws (and the corresponding color-coded "Prism" 4C Class captive screws) we manufactured offer hundreds of permutations of installation and tool-actuation styles for mounting doors, panels, and other hardware components in limited-space applications. Product Features and Benefits As one of the most popular Southco fastener styles, these versatile captive screws have evolved to provide numerous features to satisfy unique fastening hardware application needs: Numerous headstyles and installation/captivation styles accommodate a variety of material and access requirements Fit industry standard metric and Imperial screw thread sizes Provide stylized knob for hand actuation, and ratchet-mechanism or smooth knobs for restricted access Spring ejected design retracts threads when not engaged Increased torque strength though use of heat-treated steel Options for superior corrosion resistance "Prism" colored fasteners enable you to coordinate hardware to your design scheme or to differentiate access points through color Available Options Stainless steel materials and/or special finishes available for added corrosion resistance Plating options to meet aesthetic and application requirements Different materials available to suit strength requirements Standards and Specifications Restricted-Access Series and smooth-knob options help to meet UL-1950, IEC-950, and EN-60950 standards