Our vacuum screws are made for mounting vacuum compatible mounts and stages in high-vacuum environments. All of these socket-head cap screws are vented (i.e. have a hole drilled through the center) to prevent trapped air between the screw and the hole. The material is either passivated stainless steel or electroless nickel plated stainless steel. The plated screws go through a plasma surface hardening process to prevent contact corrosion between dissimilar metals. The are available in metric M4 and M6 threads and in lengths from 8 to 20 mm. If one of our catalog vacuum compatible screws does not meet your requirements, send us a request for a custom version.