I used to buy all my plastics from "Micro Plastics, Inc" but they got bought out by Essentra. I haven't bought any plastics since Essentra bought them but will need to do so soon.

Essentra part number SRS8-6-01
Mouser has these at $300/1000.

The marco part would be the same as SRS8-6-01 but in black instead of white.

SRS8-6-01 = 9.5mm standoff distance (about 3/8"), intended for an M4 (#8) screw.
Dim "B" in image = outer diameter, "C" = inner diameter, "D" = length of end that protrudes through end (add to DIM "A" to get overall length).

SRS_DIMS (resized).jpg

They came from Essentra covered in oil?!?!
Not like they're going to rust if shipped dry... That's pretty sad.

I always used Micro Plastics Inc in Flippin, Arkansas.... I always thought the town's name was appropriate. Decent prices (MUCH lower then Essentra) but you had to buy the parts in huge quantities (10Ks).

Micro Plastics was bought out by British company Essentra and the prices went sky high. Some of the parts are still made in Arkansas. The SRS8-8-01 is a part number from one of the other plastics competitors that was also gobbled up by Essentra. Not sure why they would have had the oily coating, never seen that one before. Sounds like poor parts cleaning.