The Strv m/42 had its origins on modifications in the Lago (the manufacturer designation) a 16-tonne (16-long-ton) light tank armed with a 37 mm cannon and three machine guns produced for the Hungarian Army in late 1930s by the AB Landsverk, itself a development of the Stridsvagn L-60 light tank also made by the AB Landsverk. The Swedish Army specified for a bigger and better tank than the Lago resulting in the Strv m/42 (later known as Strv m/42 TM), a 22-tonne (22-long-ton) tank armed with a 75mm L/31 gun, suited against armored and soft vehicles. The gearbox of the m/42 TM was not working well and these tanks were rebuilt either as m/42 TH, or they got a new mechanical gearbox and became known m/42 TV.