The shear strengths of solid argon and krypton have been measured by both direct and indirect extrusion techniques in the temperature ranges 32° to 81°K and 59° to 112°K, respectively. The shear strength of these materials is found to increase from 5 bars near the melting point to 100 bars near the lower temperatures indicated. Based on shear strength measurements these solidified gases are sufficiently soft and plastic somewhat below their melting points to serve as suitable pressure transmitters for high‐pressure experiments. Because their shear strengths increase rapidly as temperature is reduced, it is recommended that, where practical, pressure be applied just below their melting points and the test apparatus subsequently cooled to the temperature of interest.