The International B112 uses a 198 bulb size for both front and rear turn signal applications. The replacement chart covers 1959 to 1960 vehicle 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 198 bulb is the sole turn signal bulb type listed for the International B112, serving both front and rear positions across the 1959-1960 model years.
The 198 is an ANSI-standardized bulb, meaning it conforms to a defined North American specification recognized in both the United States and Canada.
It follows a T5 miniature wedge form factor, which refers to a small wedge-shaped base that connects directly into a socket without a separate metal base or pins.
The 198 operates at 12 volts and draws 2 watts, placing it among the lower-wattage signal bulbs in automotive use.
The Light Duty designation associated with the 198 fitment on the International B112 indicates the bulb specification applies to the lighter vehicle configuration rather than heavier commercial variants.
Because the same bulb size is listed for both the front and rear turn signal positions, no separate bulb type is required when servicing either location on the 1959-1960 B112.
The T5 wedge base format is not interchangeable with bayonet-style or indexed-pin bases, so substitution with physically different base types would not be compatible with the original sockets.