Two linear actuators driven by permanent magnet stepper motors have been introduced by motion control specialists Astrosyn International Technology. The use of PM stepper motors offers manufacturers the advantages of simple construction, high thrust and low price. However, unlike with most permanent magnet devices, minimum order quantities from Astrosyn are low, at only 100 pieces. Both the new models have a shaft stroke length of 12.7 mm with a push / pull force of 35 N. Step angles are 15 or 7.5 degrees, producing a pitch / step of 0.0254 mm and 0.0127 mm respectively. The compact units, which have a 25 mm outside diameter and weigh only 45 g, have a patented end cap on their front flange to provide extra protection to the sleeve bearing. The 12 Vdc actuators offer advantages in a wide range of applications, such as three way valve control in HVAC systems, antenna adjustment, emission control and in medical and laboratory instruments.