A butt hinge is two leaves (plates) joined by a knuckle and pin. One leaf bolts or screws to the gate stile, the other to the post or frame. They're the cheapest commodity hinge in the trade and live everywhere from internal doors to garden gates.
For steel gates, butt hinges run 100 to 150 mm tall in 3 to 6 mm plate, with a hardened pin so the gate doesn't wear the bore over time. Heavier gates outgrow butt hinges quickly. Anything past about 30 kg per leaf benefits from a weld-on hinge or a strap hinge with a longer leverage arm.
CAD60 doesn't draw the hinge plate detail itself, but it locates the hinge centres on the elevation and lists the hinge spec in the title block schedule.