The item in the picture are normally called "Machined Pin Socket Strip"
There are several different versions of these, in particular
- for small pins as typical formed IC pins or round pins approx 0.4-0.6 mm (0.015-0.25 in) dia. (similar to a machined pin IC socket, but in SIP form)
- for square 0.635 mm (0.025 in) pins, or 0.635-0.85 mm dia.
Examples from Fischer
https://www.fischerelektronik.de/- small pins MK 01 series
- large pins BL 5 series
The also come in pin pitches other than 2.54 mm (0.1 in), such as 2.0mm which I commonly use.