A Jacketed Gasket is comprised of a soft pliable core inside a metallic jacket. Metallic Jacket Almost any metal or alloy found in sheet form can be used as a jacket; its choice must take into consideration the fluid to be sealed. The metallic jacket is 0.016 in (0.4mm) to 0.020 in (0.5mm) thick. Design The following recommendations are based on successful practical applications: Gaskets confined by the inside and outside diameters: Gasket inside diameter = groove inside diameter plus 1/16 in (1.6 mm). Gasket outside diameter = groove outside diameter less 1/16 in (1.6 mm). Gaskets confined by outside diameter: Gasket inside diameter = flange inside diameter plus a minimum of 1/8 in (3.2 mm). Gasket outside diameter = groove outside diameter less 1/16 in (1.6 mm). Non-confined gaskets: Gasket inside diameter = flange inside diameter pIus 1/8 in (3.2 mm). Gasket outside diameter = bolt circle diameter less bolt diameter. Filler The standard filler material is Flexible Graphite. Other fillers like ceramic, PTFE or another metal (corrugated, flat, or serrated) can be used.