56 V Zener — voltage reference and clamping
The 1N6018A: Zener voltage is 56 V nominal at the test current, with a ±10% tolerance band — the actual breakdown sits between 50.4 V and 61.6 V, which matters for a design that needs a tight clamp threshold or reference level. Maximum power dissipation is 500 mW, which sets the continuous current ceiling: at 56 V the diode can safely conduct roughly 9 mA before exceeding the thermal limit at 25 °C ambient. Derate for higher temperatures.
DO-35 axial — board integration
Through-hole mount in a DO-204AH (DO-35) axial-lead glass package. The 0.020-inch diameter leads solder into 0.035-inch plated-through holes; the body is 0.078-inch diameter and 0.160-inch long — a standard footprint for manual or wave-solder assembly.