The saw is a metal age tool, which opens up the player to a large number new craftable objects by allowing the player to produce lumber. The saw indirectly provides an upgrade to the player's crafting grid by making planks available and is used to craft support beams from logs, allowing safe mining.
Before the player has access to an anvil a saw is created by pouring smelted liquid metal into a ceramic saw mold that was fired in a pit kiln. Next the blade must be removed from the mold by placing it in the crafting grid, and then combining the resulting saw blade with a stick.
Once an anvil has been created, a metal ingot can be directly smithed into a saw blade.