Ikea Adils table leg or 40mm tube shelf bracket.

thingiverse

Update, 27th January 2019 A new version has been added with two screw holes for mounting to underside of shelf. This is the preferred version as both sides are now more robust. Update 30th October 2017 I've made a revised version by removing the upper screw hole part on one side. This change allows a little more flexibility in the plastic around the screw clamp area. This bracket was designed to allow a full-size shelf to be fitted at any height underneath an Ikea table with Adils 40mm legs. The bracket clamps around the legs, just slide onto the leg and lock into place at the desired height using a 25mm (approx) 4mm bolt. Tighten enough to stop the bracket from sliding, if it won't twist on the leg using reasonable force, then it's tight enough. There are two screw holes in the top of the bracket for attaching to the shelf. And one hole on the updated version is available for added versatility.