PURPOSE: To measure a chill automatically, efficiently and stably, by bringing a detecting body having prescribed hardness into contact with a skin surface of cast iron under a constant load and by detecting electrically various friction forces in the case of moving either of them at a constant speed.

CONSTITUTION: The cast iron casting 1 is rotated at a constant speed through a driving motor 5 and a rotating gear 6, and the chill detecting body 8 attached at a top end of a connecting rod 7 is brought into contact with the casting surface 9 under the constant load. A current proportional to the friction force exerting between the casting 1 and the body 8 flows into the motor 5 in this time. By measuring the variation of the current by an amperemeter 10, the chill generated in the casting 1 is measured automatically, efficiently and stably.