Anyone know what these screws are called?

[JimDav]

They are called Connecting bolts. They are not elevator bolts - totally different animal. Home Depot has them. Most woodworking supply catalogs have them. Rockler.com has them - one catalog number for Rockeler is for a 2" is 31849. Page 111 in January 2012 catalog.They come in bronze and brass. They can be used with cap nuts or cross dowels. I've used them both ways. Great when building something that needs to be disassembled on occassion.

[technoronin]

Those are exactly the sort of thing I've been looking for to bolt some bookcases (not yet built) together. Please let me know what you wind up finding and where.

[evan]

Here on the Left coast there called sex bolts ... Male and Female threads

[bob_dodd]

connector bolt

[bill.young]

I buy them from Stafast.com and they call them Decorative Bolts. You can buy as few as 10, but if you buy them by the 1000 they are pretty cheap, depending on the finish. In the 35mm length, plain steel ones are about $65/1000 and black oxide are $75/1000.

http://shop.stafast.com/bolts/decorative-head-bolts

They also have matching screws with a variety of head styles...they're sort of like lag screws.

http://shop.stafast.com/screws/decorative-screws

Be aware though that shipping can get expensive...they can get pretty heavy!

Bill

[technoronin]

For my my application, it looks like "connector bolts" and "cap nuts" are the key words to search on. Thanks!

[waterwheelman]

I have used them for connecting banks of book cases together. My hardware supplier called them Sleeve screws. They come in various sizes and lengths.

[twelchPTM]

The HD around by me calls them cabinet bolts...