Q: what is the name of this part I'm trying to be this part separately but I don't really know its exact name therefore I couldn't find it.

It's the black separators highlighted in the red rectangle that I'm looking for. 
I tried looking for pin separators and pin spacers but that didn't result in anything.



A: You can buy the pin headers with different lengths of pins and pins staked into the plastic to different depths. Quite customizable. 
You can contact header manufacturers and see under what conditions they would sell them with no pins at all. I would guess that for < 1K pieces pulling them out as FM says would be your best and most economical bet, but likely short-lead-time specialist guys like Samtec as @Ignatio says might be amenable, at a price. (Ignore the name 'terminal strip', nobody else calls them that). 

You can buy headers with more than one spacer: 

To pull them out, find a piece of perf board, run the pins through (so the FR4 supports the plastic), and pull them out. If they're too grippy, warm the plastic a bit with a heat gun. 

A: As mentioned, these spacers are not sold separately (not as a standard part, anyway). However, you can buy headers just like the one you showed in your first picture with the spacers already added. I know Sullins sells some connectors like this with the option of adding these spacers within the order. It's part of the part number configuration. See the catalog page for the PPPC series (http://sullinscorp.com/catalogs/101_PAGE114-115_.100_FEMALE_HDR.pdf). In the fourth table on the first page you'll see the different options for spacers and tail length. I think this is probably what you're looking for. The top of page 2 shows how to configure the part number.


A: I think they're called pin spacers.
As pointed out by @Ignacio Vazquez-Abrams, they're not sold separately. Maybe they are, but they might be only available for other manufacturers and not for us peasants.

A: Wouldn't something like a "EW .100" Flex Stack, Flexible Board Stacker, .330" Tail" Link from Samtec work? Comes with two separators... There are other options available (don't know what you pin pitch is)...
