GRK Fasteners - Top Star Adjustable Screws

Editor's Review: Captured Nuts and Adjustable Door Jambs

The words "captured nut" may aptly describe some of the readers, many of the writers and most of the editors of this magazine, but they also describe the mechanical principle underlying GRK's jamb-setting hardware. Looking something like lag screws with free-spinning threaded collars at the driven end, they are hefty and simple to install.

After you bore a pilot hole into the jamb and framing, the adjustable screws are then driven into the jambs and trimmer studs with a (supplied) dedicated two-piece driver bit. The two-piece bit simultaneously engages the screw's castellated collar and inner Torx-head screw. With the outer portion of the driver removed, the jambs can be drawn in or pulled out by the inner screw, which supports the captured collar (seated in the jamb stock). It's neat and fleet, with no shims to slip out of alignment.

Under a tight deadline, I used this hardware to hang a couple of dozen doors in a tired old building with appallingly out-of-square openings. The doors were installed without supplementary blocking, padding or shimming and a year later are working just fine.

Editor Test Results: