12 A RMS in a TO-220 — the load rating that sets the heatsink
The STMicroelectronics BTA12-600BRG is a standard triac rated for 12 A RMS on-state current and 600 V off-state blocking voltage, housed in a TO-220-3 through-hole package.
Standard triac with snubberless capability
This part is described as a '12A STANDARD AND SNUBBERLESS TR' — meaning it can switch inductive loads like small motors or transformers without an external RC snubber in many cases, simplifying the BOM and board layout. The gate trigger current (Igt) is 50 mA max and the gate trigger voltage (Vgt) is 1.3 V max, so plan for a gate drive circuit that can source that current; a microcontroller I/O pin alone won't drive it directly.
Package and mounting — TO-220 through-hole
The tab is electrically common with the middle pin (MT2), so an insulating washer and thermal compound are needed if the heatsink is grounded. The tube shipping format is standard for this package.