The strike caused disruption but Transport for London (TfL) said Hammersmith and City and Circle line trains were running every 20 minutes.
Members of the Rail, Maritime and Transport (RMT) union called the strike amid claims industrial relations had broken down.
The drivers ended their industrial action at 21:00 BST on Friday.
TfL said a full service would be running on both lines on Saturday.
The RMT has accused TfL managers of being “heavy handed”, including putting staff toilet breaks on a stopwatch and showing “flagrant disregard” for agreed policies and procedures.
RMT general secretary Mick Cash said: “This dispute is about the basic issues of protecting working conditions of our members and defending agreements from attempts to drive a coach and horses through them.”
Despite the walkout TfL said 60% of drivers on both underground lines had turned up for work.
TfL operations director Steve White said it understood that drivers needed to take a break but said “a minority are taking breaks of an hour or more and calling them toilet breaks”, which had a direct impact on customers.
He said it was “absolutely not true” that toilet breaks were being timed, but said management was offering help through an occupational health team if a driver had issues requiring longer breaks.
