The Scleroscope is a very old hardness testing instrument, originating in the early 1900's. It is a dynamic indentation hardness test that drops a diamond tipped hammer vertically from a fixed height onto the surface of the material under test. The height of the rebound of the hammer is a measure of the hardness of the material. Scleroscopes are no longer produced in this country, however many are still in use. Two different models were produced. The C testers used a glass tube graduated from 0 to 140 to measure the rebound. The operator would observe the height of the rebound on the graduated glass tube. The D model had a 0 to 120 dial gage that would display the rebound height.

Scleroscopes are used on a wide variety of metallic parts with a limitation that the size of the sample be large enough to support the rebound. Large well-finished rolls are a good application for a Scleroscope. Special versions were also made for carbon and graphite. They do not leave an indent so the part can be used after testing without refinishing. While fairly versatile and portable, Scleroscopes are difficult to use. Standards

Scleroscope test methods are defined in the ASTM Practice E 448 standard.