Yes. You have to install it correctly. Not a professional but I suggest you weld the both bottom part on the stable gate and the top part on movable gate so you can easily remove it by pulling up.
Haven to installed yet is thick metal and appears to be able to carry 100lb gate. Plan on using three per gate
Go ahead and order the screws from Amazon (I ordered mine from a site called boltdepot.com). According to the manufacturer's drawing over at https://www.natman.com/detail/287-extra-heavy-gate-hinges-n223-867, the hinge takes #12 flathead screws. Measuring the countersink rim's diameter (after removing paint, but with a tape measure), however, I got 3/8" +/- 1/64". Spec'ing #10 alloy steel flatheads with their ASME B18.3 tolerances, I expect my #10s to sit between 0.01" low and 0.02" high.