Pre-assembled self-sealing screws and fasteners provide both fastening and sealing integrity in a single unit. Unique design features a resilient Silicone O-ring held captive in a precision asymmetrical groove under the head. Vibration-resistant and reusable screws, bolts and nuts withstand internal and external pressuresvacuum to 20, 000+ psi. When vibration is an issue, APM offers a full line of pre-applied self-locking techniques (pellets, strips, patches). SEELOC® Washers are selfsealing, vibration-resistant washers, each having a Silicone rubber section, molded and bonded to a stainless steel formed washer ideal for large or slotted holes. Positive sealing under vacuum or pressure Install like a conventional fastener Reusable & compatible with all surface finishes Metal-to-metal contact assures fastening integrity Optional O-ring seal materials – Silicone rubber, BUNA-N, *Viton®, others (see Materials & Characteristics Chart) Uniform, high-strength design Meets Military MIL-S-82496A spec for integral O-ring self-sealing machine screws UL Recognized UL Tested Optional threadlocking add-ons Optional tamper-resistent heads No chemicals to apply, no worker respiratory or environmental disposal issues