This recommended practice provides the design criteria for static elastomeric O-ring seal applications, axial compression (face type) groove dimensions for aerospace metric O-ring sizes specified in MA2010. The conditions to formulate the design criteria are also described, e.g., seal squeeze and groove volume to accommodate O-ring swell. The following static, axial compression O-ring groove categories have been incorporated: a. Internal pressure, b. External pressure. Tables of O-ring groove dimensions are included based on the design criteria specified herein. Dimensions in this document are in millimeters, unless otherwise specified.