4-51864-1 is a ring tongue terminal designed for 16–14 AWG solid or stranded wire connections. The terminal features a copper body per ASTM B-152 with tin-plate finish per ASTM B545, and includes a blue nylon insulating sleeve for electrical isolation. Key dimensional specifications include a tongue material thickness of 0.79±0.05 mm, a body diameter of 4.34±0.08 mm (0.171±0.003 inches), and a maximum overall length of 21.44 mm (0.844 inches). The terminal is rated for a maximum operating temperature of 105°C and a voltage rating of 300 V maximum, with a circular mil area of 1.04–2.62 mm² (2050–5180 CIR MILS). This terminal is commonly used in electrical harnesses, automotive wiring, and industrial control applications where reliable ring-tongue connections are required.