The chilled cast iron tappet comprises three gradient microstructures, including chill, mottle, and gray iron. In this work, the effect of Tellurium (Te) on the chilled iron tappet’s microstructure and properties is studied. The addition of Te to gray cast alloy enhances its mechanical and thermal properties, which can be used in new designing of materials for heavy automotive applications. The gray cast iron alloy with 0.01 to 0.05 wt.% of Te was prepared in order to examine the effect of Te wt.% on the chill depth, microstructure, wear, and hardness. The scanning electron micrographs are used to distinguish and analyze the chill zone, mottle, and gray zone in the tappet, and the hardness was studied by Vickers hardness test, and wear behavior by a pin on disc method was measured. The present study showed that the addition of Te strongly influenced the formation of chill and efficiently enhanced the tappet’s mechanical properties along with the favorable effect to eliminate the mottled zone and separate the chill zone and gray zone with a clear boundary. © 2021 Taylor & Francis.