Do Drawer Boxes Need Notching for Undermount Slides?

Undermount drawer slides create a clean appearance because the runners sit beneath the box instead of along its sides. That hidden position comes with specific construction requirements. The rear often needs notches, and many systems also require drilled holes or locking devices that connect the box to the runners.

The preparation should follow the exact slide model. A notch copied from another job may be too narrow, too deep, or placed incorrectly.

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Why the Rear of the Drawer Is Notched

An undermount runner travels beneath the drawer bottom and continues toward the back of the box. Rear notches create room for the runners and allow the drawer to sit at the intended height.

The notch must align with the slide position inside the cabinet. When it is wrong, the drawer may sit high, bind, fail to engage, or leave the front out of alignment.

Drawer Connection offers undermount notching as part of its custom plywood drawer ordering process. Customers select preparation that matches the planned glides.

Notching and Drilling Perform Different Jobs

The rear notch clears the runner, while a drilled hole or other machined feature may receive a locating pin. At the front, locking devices attach the drawer to the slides and allow removal or adjustment.

These features work together. Cutting only the visible notch does not necessarily make the box ready for installation.

Drawer Connection lists notching and drilling among its custom services, and its slide range includes Blum, Repon, and Salice models.

The Hardware Model Must Be Known First

Different slide families use different dimensions and attachment methods. Even products from one manufacturer may be designed for different side thicknesses, extensions, load ranges, or locking devices.

Blum describes TANDEM as a runner system for wood drawers with several side thickness options and configurations. Salice publishes separate technical dimensions for its Progressa and Futura runners. Use the current instructions for the exact model rather than a generic diagram.

A cabinet shop placing an order should provide the manufacturer, model number, nominal length, side thickness, and locking device when applicable.

Bottom Placement Must Coordinate With the Slide

Undermount hardware occupies space below the drawer. The bottom panel usually sits above the lower edge of the sides so the runners can fit beneath it.

Drawer Connection offers several bottom placement options. Its plywood guidance notes that a bottom raised 1/2 inch is commonly used for boxes receiving undermount soft close glides, while other placements suit side mount or bottom mount hardware.

Changing bottom position after assembly is not a minor adjustment. It affects the grooves, back, notches, internal height, and relationship between the drawer front and opening.

Factory Preparation Can Save Shop Time

A cabinetmaker can cut notches and drill holes in the shop, but every box must be machined consistently. Tearout, incorrect depth, and a misplaced bore can spoil a finished drawer.

Ordering preparation from the drawer manufacturer reduces those extra steps. It can be especially useful on a large run, a prefinished box, or a project using repeatable hardware.

Other suppliers offer model specific notching for the same reason. Keystone Wood Specialties provides standard and custom notching for undermount systems.

Check the Cabinet Before Installation

Correct drawer preparation cannot compensate for slides installed out of level, an opening that is not square, or incorrect cabinet clearances. Install runners according to the hardware instructions and confirm that both sides are parallel.

After the drawer engages, use the adjustments built into the locking devices or runners. Do not enlarge notches randomly to make a poorly installed slide appear to fit.

Send Complete Hardware Details With the Order

The order should identify box width, depth, height, side thickness, bottom thickness, bottom placement, slide brand, exact model, nominal length, and required preparation.

When there is doubt, send the technical sheet or contact the drawer manufacturer before ordering. One short conversation is cheaper than modifying an entire production run.

Order Slide Ready Drawer Boxes From Drawer Connection

Drawer Connection manufactures custom dovetail and dowel drawer boxes and supplies Blum, Repon, and Salice slide options. Boxes can be ordered with compatible notching, drilling, bottom placement, finish, and other details, then shipped nationwide. Call 877 917 4887 or use the online ordering system to match the box to the exact undermount hardware.