S4-40X1/2 2701, Screws & Fasteners 4-40X1/2", Slotted Pan Head, 18-8 Stainless Steel with Silicone O-Ring, Seal Screw

Self-Sealing Hardware
APM HEXSEAL Self-Sealing Hardware features fasteners and washers, including SEELSKREWS®, SEELBOLTS®, SEELNUTS®, and SEELOC® WASHERS. This reusable hardware offers positive sealing under pressure or vacuum and resists loosening due to vibration. Optional O-ring seal materials assure performance with a wide variety of gasses and liquids. APM HEXSEAL Self-Sealing Hardware is easy to install, compatible with all surface finishes, and tested and listed to UL Standard 50, Types 1-13.