The International C122 uses a 198 bulb size for both front and rear turn signal applications. The replacement chart covers 1961 to 1962 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The International C122 uses the 198 bulb for both front and rear turn signals across the 1961-1962 model years.
The 198 is an ANSI-standardized bulb type, meaning its physical and electrical characteristics conform to a defined North American specification recognized in both the United States and Canada.
The 198 bulb follows the T5 form factor, which refers to a miniature wedge-base construction with a tubular envelope approximately 5/8 of an inch wide.
The wedge-base design means the 198 bulb is held in its socket by the glass envelope itself rather than by a separate metal base with pins, a common trait in low-wattage automotive lighting applications of that era.
The 198 bulb operates at 12 volts, consistent with the 12-volt electrical systems standard in passenger and light-duty vehicles of the early 1960s.
At 2 watts, the 198 bulb draws very low current, which is characteristic of indicator and signal lighting rather than primary illumination functions.
The Light Duty designation in the International C122 specifications applies uniformly to both the front and rear turn signal positions for the 1961-1962 model years.
Because the same bulb size is specified for both the front and rear turn signal positions, the 198 bulb is interchangeable between those two locations on the International C122.