Installing Cabinet Drawers with Blum Undermount Slides

Installing Cabinet Drawers with Blum Undermount Slides

Popular Woodworking shows how to install cabinet drawers with Blum Tandem undermount slides, featuring an integrated soft-close that activates during the final inch of closure.

The slides are mounted in the cabinet’s 5mm dia. system holes and use 5mm x 13mm Euro screws, ensuring a precise setback and parallel alignment with the cabinet top.

Choosing the Right Slides

Blum Tandem slides and inset locking devices simplify drawer installation. The locking devices attach to the drawer’s bottom, each with an adjustment lever that moves the drawer up or down in small increments. A second lever at the back of each rail raises or lowers the drawer’s rear, allowing the front to sit flush with the face frame. A third adjustment screw on each locking device slides the drawer in and out, aligning it perfectly.

Because the slides are designed for the 32mm system, drilling 5mm holes in the cabinet sides automatically positions the slides with the correct setback and parallelism, speeding up the process.

Preparing the Drawer Box

The drawer box must be modified for undermount use. First, cut 1-3/8″ wide by 1/2″ deep notches in the back, adjacent to each side. The notches should just graze the drawer bottom. Use a pair of stopped passes: cut the notch, stop the saw, reset the fence, and cut again to finish.

Next, drill a 6mm dia. by 10mm deep hole just above each notch. For a single drawer this can be done by hand; for many drawers a manufacturer’s jig speeds the process.

Use the same jig to drill pilot holes for the locking clips that engage the slides. These clips sit on the underside front corners of the drawer and are installed with #6 x 1/2″ truss head screws at a slight angle. One left and one right clip are required per drawer.

Installing the drawer box is simple: place the drawer onto the slide rails, push it into the opening until the locking clips engage at the front and the pins engage at the back. To remove the drawer, pull it out, reach under, and squeeze the locking clips.

Installing the Drawer Front

Begin by drilling two 5/16″ holes in the front of the drawer box, 1″ down from the top and 1-1/2″ from the inside face of the side. Use a brad point bit and a scrap wood backer to avoid tear-out.

Trim the drawer front to fit the opening with 3/32″ gaps all around and use shims to center it. Mark pilot hole locations on the front’s back by pushing the same drill bit through each hole from inside the box and twisting it. Drill #8 pilot holes into the back of the drawer front using these marks, ensuring perfect centering.

Attach the front with #8 x 1-1/8″ washer-head drawer-front mounting screws. The oversized holes in the drawer box allow nearly 1/16″ adjustment in any direction, so the front can be fine-tuned after cabinet installation.

Install the pull only after the cabinet is assembled and the front is centered. Drill holes sized to match the shanks of the mounting screws through both the drawer front and the drawer box. For tall drawers, add angled screws from the bottom of the drawer box front into the applied front to secure it further.