This SAE Recommended Practice is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances. This document establishes performance requirements@ material requirements@ design requirements@ and design guidelines for headlamps. Rationale Revisions to SAE J1383: a. Moved replaceable light source requirements to SAE J2560. b. Moved sealed beam headlamp requirements to SAE J2595. c. Removed fractional aim headlamp requirements since these requirements are applicable to sealed beam headlamps. d. Revised and updated section 4 Identification Code@ Markings and Notices in its entirety to remove sealed beam markings and add visual/optical aim markings. e. Revised Thermal Cycle Test temperatures from ?30 ??to 48.5 ??to ?40 ??to 50 ??to more accurately reflect the typical global ambient environments (does not account for really cold climates@ e.g. Fairbanks Alaska ?50 ??. f. Moved out-of-focus test to the guidelines section. Improvements in light sources@ computer-aided optical design@ and light source manufacture have made physical testing of parts unnecessary. Out-of-focus testing@ when necessary@ can be performed on the computer rather than with physical parts. Experience has proven that with current production light source tolerances and the proper selection of design parameters for lamps@ there is no need for any out-of-focus testing in many cases. Therefore@ the test was moved to the guidelines. g. Added section for visual/optical aim feature design requirements including methods for horizontal visual/optical aim. h. Added mechanical aim (VHAD) aiming requirements. i. Revised and updated headlamp photometric requirements to more clearly define requirements. Added design to conform statement in guidelines section and changed to the SAE standard of one photometric table for requirements. In addition@ changed 4D test points to be tested as scan lines with a maximum requirement a percentage of a test point in the down-road seeing light. The scan line is more beneficial than a point for controlling the light in the foreground region for a reasonable contrast.