Plastic key heads break after some time. We can replace them with wooden key heads, so we don't have to use a pair of pliers to turn the key in the lock everytime.
We start off with a nice piece of 3mm plywood.
The metal key is 2.8mm thick, so three pieces of plywood will encase the key in a wooden key head.
Cut out the three pieces of plywood. The metal key determines the size of the key head.
The three pieces of wood are glued together.
The raw key head is drilled for work holding in the mill.
After milling, the plywood edge forms a nice layered look.
The metal key is glued into the key head.
The key is ready for use.