Properties of seal materials are described. Leakage and wear of hydraulic cylinder piston and piston rod seals were tested. Considerable differences in the leakage of different seals were measured in a static test at the temperature of −50°C. Severe wear of a specific low temperature nitrile rubber piston seal occurred when the piston was driven through 162 000 strokes at normal temperatures.O-rings made of six different materials were tested in the temperature range −60…+60°C. Special nitrile rubbers and fluorosilicones produced the best performance. Standard nitrile O-rings are not recommended for use below −40°C.Seven radial lip seals were evaluated at +20… −40°C. Silicone seals produced the best performance at low temperatures.