Aegis II Linen Melamine Ferrule with 5/16-18 thread thru inside Length>Aegis II is a Linen Melamine based thermoset ferrule material. It is rolled and molded for high strength. It bonds well with Epoxy, Cyanoacrylate, and wood glues. Machines well, and the color varies from soft white to Ivory. Internal thread is 5/16-18 with a .562" outside diameter.