This SAE Aerospace Recommended Practice (ARP) is intended to provide definitions of and recommendations for drawing limits pertaining to surface and edge features on machined metal fluid fittings and is subject to change to keep pace with experience and technical advances. The subject includes: features, descriptions and definitions, examples, limits, inspection methods and standard drawing callouts where applicable. Fittings may retain unmachined material surfaces that exhibit similar surface features as machined surfaces and may be inspected to the same criteria. These unmachined surfaces may also contain unique features that are addressed separately. See

Figure 1 for the relationship of surface and edge features.