Does anyone know what these screws are called?

Hi,

I am trying to build a cot bed and we have lost some parts to complete it, the manufacturer no longer has them and no amount of googling has returned anything like the picture.
Any idea what the real name for the metal studs, coarse thread at the top of the image is, where I can buy some, or an alternative screw that will do the same job?
Any help appreciated! Thanks.

 

They fix the base and the top to the side panels which then connect to the cot ends. I've attached a picture.

 

Thanks they are very similar although they have a hole in the end.

 

Thanks so much! Will give the website a try.