Unslotted - Hex Washer - Neo-EPDM Washer - Self Drilling Screws - Silver Ruspert

Used in metal roofing to create a leak-proof seal.
Screw is Case Hardened to Rockwell C52-58
(Core Hardness: Rockwell C32-40)
Steel Silver Ruspert Finish / 1,000 Hour Salt Spray Rated
High Corrosion Resistance