Blum 563H Tandem Plus Blumotion 21" Soft-Close Full Extension 90 lb Undermount Drawer Slide, Zinc, 03469549

Undermount Drawer Slide For Deep Kitchen and Bath Drawers

The Blum TANDEM plus BLUMOTION 21 inch undermount slide is a concealed, full-extension runner with integrated BLUMOTION soft-close, sized for the deeper drawer boxes common in base cabinets, bathroom vanities, and pantry drawers. It carries 90 lb per pair on roller bearings and fits boxes built with 1/2 to 5/8 inch drawer sides.

Key Features

• Full extension at 21 inches — the entire drawer box travels out to the cabinet face, putting the back of deep storage within reach.
• Integrated BLUMOTION soft-close — Blum's damper mechanism catches the drawer near the end of travel and settles it shut silently.
• 90 lb capacity per pair — handles loaded pots-and-pans drawers, heavy utensil storage, and stacked pantry goods.
• Roller-bearing steel construction with zinc finish — smooth, quiet travel with corrosion resistance for years of indoor service.
• Suits face-frame and frameless cabinets — a single slide model that installs in both construction styles with the appropriate series hardware.
• 3/16 inch side clearance — precise spacing requirement that determines your drawer box width relative to the cabinet opening.

Where the 21 Inch Length Makes the Difference

Drawer slide length follows cabinet depth, and 21 inch slides serve the deeper base-cabinet drawers where most of a kitchen's daily-use storage lives. A standard 18 inch slide leaves a shallower box; stepping up to 21 inches accommodates the extra depth in a 24 inch base cabinet run or a bathroom vanity built to hold full-size toiletry organizers. Full extension at this length means the rear of that deeper box is accessible without reaching blindly to the back — a meaningful difference when the drawer holds heavy pots or stacked containers.

Build and Construction

Steel members with a zinc finish give the slide its durability in normal indoor environments. The roller-bearing carriage runs quietly under load and holds its feel over time. Because the slide mounts entirely beneath the drawer box, the zinc finish serves a protective rather than decorative function — nothing shows when the drawer is open. BLUMOTION soft-close is integrated into the slide body, so there are no separate damper clips to lose or replace.

Who This Slide Is For

Cabinet shops running deeper base-cabinet drawers on production builds will find the 21 inch TANDEM plus BLUMOTION a straightforward stock item — it handles face-frame and frameless construction from the same SKU. Designers specifying soft-close concealed runners for residential kitchens or bath vanities get a proven Blum system with a predictable installation process. Contractors doing drawer upgrades in existing 24 inch cabinetry can match the depth without stepping into an oversized slide. For 3/4 inch drawer sides, a different 563H configuration is the correct choice; this version is built around 1/2 to 5/8 inch material.

The Right Slide for the Job

Match the 21 inch length to your drawer box depth, build the box to Blum's specification, add the series hardware your cabinet construction requires, and the TANDEM plus BLUMOTION delivers full-extension access and silent soft-close for the life of the cabinet.