International S122 headlight bulbs utilize the H6024 size for both high and low beam functions. The replacement chart covers 1956 to 1957 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The H6024 is a 7-inch round sealed beam unit operating at 12V. Unlike modern halogen or HID bulbs, a sealed beam integrates the filament, reflector, and lens into a single non-serviceable assembly, meaning the entire unit is replaced rather than an internal bulb.
The H6024 follows the ANSI standard recognized in both the United States and Canada, placing it within a standardized sizing and performance classification system used across North American vehicle manufacturing.
The International S122 uses the H6024 for both high beam and low beam functions across the 1956-1957 model years, indicating a single sealed beam unit serves dual lighting roles rather than separate dedicated assemblies for each function.
Because the H6024 is a sealed beam format, fitment is governed by the physical housing size and electrical connector rather than a separate bulb socket. Substituting a non-sealed-beam type would require modification to the headlight housing.