What is the technical term for this?

[Herb G]

I know it's a 3/8" X 16 TPI threaded insert. I have Googled until my fingers bled, but I can only find them at pen supply places for nosebleed prices. It's used for bottle stoppers.

[arthropod98]

i believe it's "threaded insert".

[Cooler]

Yes, but that type is designed for insert molding of plastics.  You want one that is designed for wood.

Here are some examples:  https://www.google.com/search?q=threaded...oQ_AUIBygC

Make many inquiries.  These can be very expensive or pretty cheap depending upon where you buy them.  Shop and you will get a good deal.

[arthropod98]

doh, i just read that you said "threaded insert". 

[arthropod98]

here's the one i thought was pretty interesting:

http://www.rockler.com/riveting-t-nuts-a...rting-tool

[Hank Knight]

It's called a "knurled threaded insert" or a "knurled press insert." Google it and you'll find photos and info on where to buy.

[daddo]

Post a pic of your bottle stoppers.

[EdL]

Essentra (formerly Reid Supply) has them. McMaster Carr also.

Threaded inserts

Ed

[Herb G]

Essentra (formerly Reid Supply) has them. McMaster Carr also.

Threaded inserts

Ed

They have threaded inserts, but none like the pic.

[EricU]

mcmaster has too many choices.  They have plastic, wood, hardwood. https://www.mcmaster.com/#standard-threa...s/=15sd8w6
They seem to think that the one you show is for metal

I believe most people would call it a "press-in knurled threaded insert" or some scrambling of those terms. Grab what's inside my quotes and search google, you'll find lots. But you may be unhappy at the price unless you want a quantity