These are lead frame pins, which are edge mounted on a standard 64mil / 1.6mm thick PCB. Pitch is 100mil / 2.54mm spacing. Thickness is 10mil / .25mm. They allow mating with DIP sockets without causing issues with the socket.
The lead frame pins are copper tin (aka phosphor bronze). They can be plated if desired. Are mounted easily by hand soldering. Or can be sent to a PCB manufacture to be assembled on your project. Once soldered to the PCB you simply bend the top and bottom part of the strip to break and remove it. Or You can simply cut the bottom off with standard scissors to set the desired length of the legs.
Round or square header pins have been used in the past to create a PCB with IC legs. However these unfortunately all damage dual-wipe sockets once mated. And once removed, an IC is no longer able to be installed in the socket and provide reliable contact. In contrast, the lead frame pins are designed for this application and do not damage sockets in any way.
Comes in units of 20, 40, and 100 pins. See pics for recommended footprints when designing PCBs. Main picture is for example only. You will receive the amount of pins you specify in a strip as pictured.