Things You'll Need
2 bolt hooks
Phillips head screwdriver
2 identical single-acting hinges
3 or 4 short bolts per hinge pair
3 or 4 nuts per hinge pair
Hinges come in a variety of types and sizes, each used for a different purpose. Some of them swing both ways, including the simple bolt-hook-and-strap hinge as well as the more complex double-acting spring hinge. These hinges are available at most hardware stores, though it is possible to design your own hinge with individual items purchased at the store. Bolt-hook-and-strap hinges can be bought in parts. Double-acting hinges can be built from two single-acting hinges, though it is more reliable and sturdy to use a store-bought double-acting hinge.
Designing a Bolt-Hook Hinge
Choose a bolt size appropriate for the weight of your gate. Larger gates should use thicker bolts. For a small wooden yard gate, a 1/4-inch bolt will work fine.
Measure 6 inches from the top of where the gate will be attached to the post or fence.
Screw the bolt hook into the post. Use a pair of pliers to help tighten it into the wood. Screw it in far enough that the hook points directly upward.
Measure 6 inches from the bottom of where the gate will be attached to the post or fence.
Screw the second bolt hook into the post at the bottom. Use a pair of pliers to help tighten it into the wood. Screw it in far enough that the hook points directly upward.
Hold the gate off the ground where it will be hung. Mark with a pencil where the bottom edge of the hook rests against the gate for both hinges.
Place the strap hinges against the gate so the bottoms of the hinges are at the marks you made with your pencil. Attach the strap hinges with screws so the open end is flush with the gate.
Lift the gate and slide the strap hinges onto the bolt hooks. The gate should rest completely on the bolt hooks and swing both ways.
Designing a Double-Acting Hinge
Purchase two identical single-acting hinges for each hinge placement. Many different types of hinges are available, so be sure the hinges you purchase are identical and will line up with one another.
Place the two pieces against each other with the hinge action on opposite sides. Line up the bolt holes on the center flanges with each other.
Bolt the two flanges together with appropriately sized bolts and nuts. Use shorter bolts so they, and the nuts, are as close to being flush with the outer hinge flanges.
Double-action hinges are available at most hardware stores and can be installed by bolting one flange to a flat jamb or post while the other flange is bolted to the edge of the gate.