Abstract: A screw cap for a container that has a thread, in particular bottles, jars, and the like. A ring that incorporates at least one projection engages the thread on the container. The ring can be configured as a safety ring, i.e., that it have a lower ring section that incorporates barbs that extend from a perpendicular wall area. When the container is first opened, the barbs engage under projections on the container and burst the lower ring section off. The cap of the screw cap need incorporate no threads of any kind because of the projections of the ring.