1/4-14X7/8 Unslotted - Hex Flange With Rubber Washer - Self Drilling Screws - #1 Stitch Point - 1,000 Hour Rated High Corrosion Resistance
Bearing surface of flange is undercut, allowing rubber washer to form a tight seal when screw is fully installed.
Screw is Case Hardened to Rockwell C52-58
(Core Hardness: Rockwell C32-40)
Steel with 1,000 Hour Salt Spray Rated Finish