The 1.5KE13A-G: The reverse standoff voltage is 11.1V typical — this is the DC rail voltage the diode leaves alone during normal operation. Breakdown occurs at 12.35V minimum, so the diode stays off below that threshold and starts conducting only when the transient pushes the line above it.
Package, mounting and the reflow-free build
Through-hole axial package in DO-201AA / DO-27 form factor, supplier device package DO-201. No reflow profile to worry about — this part is hand-soldered or wave-soldered into the board. The axial leads sit flat on the pad; tombstoning is not a concern with through-hole parts. Operating junction temperature range spans -55°C to 150°C, so it handles the thermal extremes of industrial and automotive environments without derating the pulse power capability at the high end.