This automatic center punch makes an indentation, used as a guide, to keep your bit from wandering and scratching your metal when you drill. Because it is spring loaded, there is no need for a hammer.
To prevent your drill bit from moving off the mark when drilling, line up the tip of the punch where the hole will go. No need to hammer. Just press down and the spring-loaded auto punch does the work for you, leaving an indentation that you can place your drill bit into.
If you are using this tool on extremely soft metal or metal thinner than 24 gauge, do not use a steel bench block under the metal. On the thin or soft metals, this punch will indent so hard that you might dent your bench block.