A cooper was someone that made or repaired wooden containers and barrels. This tool, the concave sun-plane, was used to smooth out the tops and bottoms of the staves after the container was put together.
The froe is used to split wood into slabs or thin wedges. The cooper used the froe to quarter split a block of wood into wedges to make staves. The froe is held with the metal head against a piece of wood and the handle in the air. It would then be hit with a mallet to create a clean, rectangular split in the wood.
The cooper used a croze to cut a groove into the bucket or barrel so the lid or bottom would fit securely against the wood. The cooper had to make sure the pieces of wood fit tightly together so none of the contents, such as milk or grain, would seep out.