The Type 61 (61式戦車) was a main battle tank (MBT) developed and used by the Japan Ground Self-Defense Force (JGSDF), built by Mitsubishi Heavy Industries.Development started in 1955 and the vehicle was first deployed in April 1961. The type number follows the year of deployment. A total of 560 Type 61s were manufactured between 1961 to 1975, when production ceased.