Research on the symmetric toroidal pinch (STP) has been carried out at Nagoya during the past 15 years. From 1970 to 1982, this research concentrated on heating and confinement of screw pinch plasmas with force-free currents. Reversed-field experiments in metal tori started in 1983. The main object of these experiments is to study transport processes in reversed-field pinches with high current density (5–10 MA· m−2) At present, plasma currents up to 15 MA (6.2 MA· m−2) can be driven during 1.6 ms. Toroidal flux enhancement and related phenomena are being investigated.