From the Manufacturer
Use PHEINOX™ stainless steel fasteners in tropical wood, cedar wood, pools, hot tubs, saunas and seaside applications, as well as deck applications in areas with large daily temperature variances.
For best results, trim screws should be driven at half-speed. To prolong the life of the #10 bit, do not use an impact driver on the #8 trim head screw.
GRK Fin/Trim™ Screw