Grass Dynapro Undermount Slide Built for Thick-Sided Drawer Boxes

This is the Grass Dynapro 21 inch heavy-duty undermount slide engineered for drawer boxes with 5/8 to 3/4 inch sides — a full-extension, soft-close concealed runner rated 132 lb per pair, suited to demanding kitchen and bath drawers where thicker box stock is the standard.

Key Features

• 132 lb per pair capacity puts this slide in heavy-duty territory, handling loaded utensil, pots, and pantry drawers without strain.
• Full extension brings the entire 21 inch drawer box out to the cabinet face so the back of the drawer is fully reachable.
• Integrated soft-close catches the drawer near the end of travel and settles it shut silently — no slamming, no add-on dampers needed.
• Designed for 5/8 to 3/4 inch drawer sides, covering shops that build from thicker hardwood or 3/4 inch plywood stock.
• Built-in Dynapro synchronization keeps both slides of the pair tracking together on wide drawers, up to 48 inches, without an add-on synchronization rod.
• Steel construction with zinc finish on a roller-bearing carriage delivers smooth, consistent travel through years of daily use.

Where This Slide Earns Its Place

The standard Dynapro line is spec'd for 1/2 to 5/8 inch material. This heavy-duty version extends that range to 3/4 inch, which opens it up to shops building drawer boxes from solid hardwood, thick Baltic birch, or 3/4 inch domestic plywood. It also carries the higher 132 lb rating, which matters on the jobs that push standard undermounts to their limits: double-drawer pots-and-pans pullouts, fully loaded pantry drawers, and wide file or utility drawers in residential and light commercial work. The 21 inch slide length suits base cabinet drawers in the 21 inch depth class — the most common depth in residential kitchen construction.

Construction and Motion Details

The slide body is steel with a zinc finish — a functional, indoor-rated finish that stands up to humidity cycles in a kitchen environment. The roller-bearing carriage provides a smooth, quiet pull under load without the breakaway feel of an unloaded ball-bearing slide. Dynapro's built-in synchronization means the left and right slides move as a matched pair without lateral shimmy, which is particularly noticeable on drawers wider than 24 inches. The integrated soft-close damper requires no adjustment and no separate hardware — it is part of the slide from the start. Minimum installation depth is 21-27/32 inches, and side clearance is 6mm per side, so plan the box width accordingly.

Who Should Order This Slide

Cabinet shops standardizing on 3/4 inch drawer-box construction will find this slide fits their material stack without switching to a different thickness version mid-project. Custom builders and finish carpenters working on premium residential kitchens get the concealed look with load capacity that keeps pace with heavy pulls on loaded drawers. The slide suits both face-frame and frameless cabinets — in face-frame installations, add the series-specific Dynapro rear mounting brackets, which are not included and do not interchange with other brands' hardware. Dynapro front locking devices are also series-specific and sold separately; the box must be built to Grass's specification for this series, including the correct box width for the 6mm side clearance, a bottom recess, rear notch, and locking-device drilling.

Match the Slide to Your Build

When the drawer box calls for 3/4 inch sides and the load demands more than a standard undermount can carry, this Dynapro heavy-duty slide covers both requirements in a single, fully concealed 21 inch runner.