Teachers at Kingswinford School in Dudley struck on Thursday of last week in protest at plans to turn it into an academy.
The action, by NUT and NASUWT union members, shut the school.
The school plans to convert to an academy on 1 January. Teachers there previously struck for one day last month.
Meanwhile, teachers in Wembley in north London are considering a series of rolling strikes over plans to turn a school into an academy.
Preston Manor Foundation School is considering becoming a privately run academy. Several other schools in the borough are also battling against being turned into academies.
Teachers at a MediaCityUK academy in Salford have announced more strike dates in their fight to stop job cuts.
NUT and NASUWT union members at are set to strike on Tuesday and Wednesday of next week and on Tuesday and Thursday the week after.