Today will be the day you finally learn how to properly use a hammer because TikToker @adrian_mountainman_sr posted a video that explains how to hold a nail and hammer so you avoid hitting your thumb. The TikToker shows how to fit a nail into a groove on top of the hammer for a safer swing.
Hammers with a small indent on the hammerhead with a small disk inside the notch help you hammer in nails that are difficult to hold. Redditor Cojesa said, “The small circular insert is a magnet. It's to hold small nails in place on the hammer so you don't hit your thumb.”
Hammers with specific grooves and sharp “puller” teeth can hold large nails on the head, and since it’s also a magnet, it can even hold nails while tipped upside down. This allows people to reach overhead or hard-to-reach corners.