What is this detail called? Bought furniture at a flea market and missing a couple.

[nimhed]

So the round plug with a thread that the screw attaches to

 

[Björn Melander]

Sargsprint

 

[nimhed]

Just found it myself too. Thanks

 

[rävlyan]

IKEA's plug for assembling cabinets and furniture, available in their spare parts boxes, can be purchased by weight or for a coin in the donation box.

 

[nimhed]

IKEA's plug for assembling cabinets and furniture, can be found in their spare parts boxes, sold by weight or a coin in the box

Good tip when you only need a few (and live close to a store).