In this paper

the temperature distributions and solidification processes in aluminum alloy rode-shaped castings with steel chills are experimentally monitored and numerically simulated. The heat absorptions in the chills are calculated as the function of the time from the experimental and numerically calculated results. The effecient chill chickness Heff （mm）

which will be directly used for chill thickness choising

is obtained by comparing the heat absorption calculation and the solidification time in the casting. With an aim of design of chills

the cooling surface factors （k） of the chills for aluminum castings are given. The inference of the chill thickness and the casting thickness on the k is also discussed in this paper.