Stolmen and Ekby compression bookshelf system

Step 4 "Sandwich" bolts

1/4" x 20 x 2 round-top bolts

This is the bolt that runs through the two brackets sandwiching the shelf, which tighten the brackets to hold the shelf in place.  The bottom screw is exposed at 2"—I was tempted to try acorn nuts like Lucien's solution but the effect is negligible.

 

Bolts:  $2.30 for a pack of three

 

Last bit about DrillSpot.com:  they offer Google Checkout which means you get significantly cheaper shipping than any competitor.  Other resellers charge as much to ship as the damn parts cost and take a percentage on returned product, too.  Boo.