Quick Answer
A drawer slide or runner guides a drawer as it opens and closes and supports it in the installed cabinet. Choose one by its exact mounting requirements, extension, loading conditions, and drawer construction. Length and a headline load rating are only part of the specification.
Select the slide before making a replacement drawer box. Two runners with the same nominal length can require different clearances, drawer-bottom positions, fixing points, and cabinet depths.
Separate Mounting Position from Running Mechanism
The usual slide descriptions overlap rather than forming one list of mutually exclusive types.
- Mounting position: side-mount runners attach at the drawer sides; concealed undermount runners sit beneath the drawer; center-mount systems have another arrangement.
- Running mechanism: rollers, ball bearings, and other guided systems describe how the moving members run.
- Extension: partial extension leaves some drawer depth inside the cabinet; full extension improves access to the back; overtravel extends farther on products designed for it.
- Closing or opening feature: soft-close, self-close, and push-to-open describe additional behavior, not a universal mounting pattern or load class.
A ball-bearing runner may be side mounted, and a concealed runner may provide soft-close. Do not select an alternative by matching only one of those descriptions.
Dimensions to Confirm Before Cutting
| Dimension or detail | Why it matters |
|---|---|
| Clear cabinet opening | Controls the available width and whether a face frame obstructs the runner |
| Required side clearance | Affects drawer-box width; use the exact runner drawing |
| Available cabinet depth | Must accommodate the runner and any rear mounting parts |
| Drawer side thickness | Some concealed systems accept only specified thickness ranges |
| Drawer bottom position | Affects clearance over undermount hardware and locking devices |
| Rear notches or holes | May be required for hooks, pins or adjustment hardware |
| Door and hinge clearance | An opening door or hinge arm may obstruct an internal pull-out |
Measure the finished opening at front and rear. A cabinet that tapers or twists cannot be corrected by making both slides parallel only at the front.
What a Load Rating Actually Covers
Check whether the published rating applies to a pair, a complete runner system, or an individual component. Include the drawer box and attached front in the moving load as required by the maker. A rating for vertical side mounting should not be transferred to flat mounting unless that orientation is expressly permitted.
Drawer width, length, mounting method, extension, and test conditions can affect the allowed application. A wide tool drawer can also rack or twist differently from a narrow cutlery drawer. Use the exact product documentation rather than assuming all ball-bearing slides or all undermounts carry the same load.
Blum’s TANDEM product range, for example, distinguishes variants by extension, nominal length, side thickness, and load class. Those details illustrate why one advertised family name is insufficient for cutting a drawer box.
Installing in Face-Frame and Frameless Cabinets
In a frameless cabinet, the box sides often provide the mounting planes. They must still be sound, straight, and spaced for the chosen runner.
In a face-frame cabinet, the frame may project inside those planes. Approved spacers, blocking, or a rear mounting bracket may be needed. The runner should not bend inward to meet the cabinet side behind a projecting frame.
Use the manufacturer’s fixing locations and suitable fasteners. Adjustment slots help with positioning, but the final connection must meet the installation instructions. A screw driven through a damaged hole is not a reliable fixing just because the slide initially feels smooth.
Diagnose Binding Before Replacing Hardware
Remove the drawer’s contents and inspect for debris, loose screws, protruding screw heads, damaged runners, and failed locking devices. Check that the cabinet is square and that both runners are level, parallel, and at matching heights.
If the drawer runs freely until the final part of travel, investigate the closing mechanism and engagement. If it binds throughout travel, inspect spacing, twist, and drawer-box dimensions. For a drawer that disengages or lifts, check its locking devices and required rear connections rather than adding arbitrary screws.
Lubricate only as instructed. Unapproved oils or greases can attract dirt or interfere with materials and mechanisms. Replace a damaged or overloaded product with a compatible system rather than treating adjustment as a cure for physical failure.
A Useful Buying Checklist
Bring the existing part number, photographs, opening dimensions, drawer dimensions, and intended contents. Confirm the required extension and removal method, then obtain the installation drawing before committing to the replacement. A slide is a connection system between a particular drawer and cabinet, not a generic metal strip selected by length alone.
References
Use the runner manufacturer’s current drawing for exact dimensions and loading conditions. Product-family examples below are not interchangeable installation instructions.