SAE J448, Surface Texture, has been set up for precision reference specimens using a controlled surface profile to obtain reproducible roughness values. These specimens are for instrument calibration. Appropriate symbols for roughness, waviness, and lay have also been standardized (ASA B46.1-1962 and SAE J448).
For production control, especially from one geographical location to another, means are required to facilitate the inspection of surface characteristics called for by specifications which include not only roughness but profile waviness and lay. In order to integrate the requirements of the designer with the actual production of surfaces, a second grade of control standards must be adopted which will be functional in nature for the specific product being manufactured. These control standards may be Calibrated Pilot Specimens (actual parts with satisfactory texture) or Roughness Comparison Specimens (ASA B46.1-1962). This SAE Recommended Practice describes the usage of these control standards.ese control standards.