National Engineered Fasteners is a distributor of Mil Spec O-rings. Mil Spec O-rings are available in standard & metric sizes for applications including aerospace, automotive, hydraulic, pneumatic, critical sealing, medical, semiconductor, military, industrial equipment, & appliances. Standard sizes for mil spec o-rings include AS, MS, MIL, AMS, AN, NAS & SAE. All mil spec O-ringsare dfar compliant.