Abstract: A thermal distortion tester for testing thermal distortion of a sand specimen, comprising a gimbal to support the sand specimen, an actuator to raise and lower the sand specimen, and a hot surface, wherein the sand specimen is brought into contact with the hot surface at a pre-determined pressure or pressure profile. The temperature of the hot surface is maintained at a pre-determined temperature or temperature profile. The distortion of the sand specimen while applied to the hot surface is directly measured through measurement of the longitudinal movement of the gimbal, and radial distortion is measured by a micrometer camera. The temperature gradient of the sand specimen is also measured throughout the duration of the test. A method of using the same is also described herein.