Replacement means matching an envelope, not just a length
A compatible replacement soft-close drawer slide must fit the cabinet, drawer box, mounting points and release system. The same nominal length or load rating does not make two slide families interchangeable.
First identify the existing mounting type. Then record the complete space available, the box geometry and the model-specific installation requirements. This checklist helps decide whether replacement is direct, needs approved modifications or calls for a different drawer.
Identify what is actually installed
Empty and support the drawer before releasing it, following the existing manufacturer’s removal instructions. Photograph each rail, the front locking devices, rear brackets and any stamped identification. Keep left and right components together.
| Existing system | Clues to record | Why the replacement can differ |
|---|---|---|
| Side-mount ball-bearing | Rails at both sides; closed length, section height/thickness and disconnect design. | Side space, hole pattern, front setback and rear supports may not match. |
| Concealed undermount | Runners below the box, front locks and rear hooks or fittings. | Inside box width, wall thickness, bottom recess, rear preparation and locking devices can be system-specific. |
| Integrated drawer / metal-side system | Proprietary drawer sides and runner connections. | The runner may be part of an integrated system rather than a stand-alone rail. |
| Unknown or damaged system | Photograph the complete assembly and preserve readable markings. | A visually similar slide is not sufficient evidence of compatibility. |
For a broader explanation of mounting types, use Drawer Slides 101. That guide helps name the hardware; the worksheet here addresses whether a replacement physically fits.
Replacement soft-close drawer slide compatibility checklist
| Check | Side-mount replacement | Undermount replacement | Decision evidence |
|---|---|---|---|
| Nominal and physical length | Measure the fully closed rail; check cabinet depth and support engagement. | Use the required drawer length and cabinet-depth relationship from the exact runner drawing. | Current and replacement model drawings. |
| Width envelope | Measure cabinet mounting planes and outside drawer width at several positions. | Record both inside and outside drawer width and actual side thickness. | Actual dimensions and the specified tolerance. |
| Vertical envelope | Rail profile and screw-head clearance. | Bottom recess, bottom thickness, front-lock space and rear preparation. | A cross-section for the supplied model. |
| Mounting | Front setback, fixing holes, face-frame blocking and rear brackets; confirm fit before using 45mm drawer slide brackets. | Correct front locks, rear hooks, brackets and fixing substrate. | Approved installation components, not old parts by appearance. |
| Movement | Extension, disconnect and soft-close engagement. | Locks and rear fittings fully seat throughout the approved motion. | Same-family components and observed operation. |
| Load | Use the manufacturer’s definition and mounting orientation. | Include the completed drawer and its contents as required by the rating. | A slide rating is not a rating for the drawer bottom or cabinet attachment. |
Measure the complete cabinet and drawer envelope
Record the cabinet’s clear width at the actual rail mounting planes—not only the front opening. In a face-frame cabinet, the frame can reduce the opening while the interior sides sit farther apart. Blocking and rear supports must locate the runners on the intended planes.
For example, a 500 mm clear width and 474 mm box leave 26 mm total, or 13 mm per side only when centered. That arithmetic does not establish whether a particular nominal 12.7 mm rail is approved for the available space. Use the manufacturer’s installation tolerance and measure front, middle and rear.
Accuride’s side-space guidance explains why both tight and excessive space can interfere with slide operation. Its model-specific allowances are examples, not Berta installation dimensions.
Measure the inside cabinet depth to the nearest obstruction and record rear-bracket space. Separately measure the drawer-box length, front projection and any inset setback. Do not treat the decorative drawer front as part of the box length unless the relevant drawing defines it that way.
Undermount replacements need a box cross-section
Record the actual side-wall thickness, inside width, bottom thickness and the vertical distance from the bottom of the side to the underside of the bottom panel. Also measure rear notches and hook bores, front locking-device locations and the space behind the front.
Berta’s current undermount product gallery contains more than one side-thickness configuration, while the selector chooses slide length. Before calling a replacement compatible, obtain the drawing that belongs to the supplied kit. Do not combine an inside-width deduction from one illustration with rear preparation or locks from another.
The drawer-box thickness and slide-compatibility chart explains how changing side thickness changes inside width. For the runner’s function, read the full-extension undermount guide.
Do not buy a longer screw or force the clips to compensate for a mismatch. A screw can pierce the drawer interior; an incompletely seated lock or rear fitting can leave the drawer unsecured. Verify the actual locking system and fixing path.
Current Berta slide families to evaluate
| Product family | Listed lengths | Mounting / listed section | Pack and components | Replacement caveat |
|---|---|---|---|---|
| Soft-close ball-bearing side-mount | 12, 14, 16, 18, 20, 22 and 24 in | Side mount; listed thickness 12.7 mm and 45 mm profile. | 10 pairs, face-frame brackets and installation screws. | A listed rail thickness is not a complete installation tolerance or proof old brackets fit. |
| Soft-close concealed undermount | 12, 15, 18 and 21 in | Under the box; obtain the matched drawer cross-section. | 10 pairs, locking devices, rear brackets and screws. | Confirm the side-thickness configuration, box geometry and exact fittings. |
Both listings state a 100 lb rating, but a shared number does not make the mechanisms interchangeable. The drawer construction, mounting method and fasteners still must satisfy their own requirements. Confirm the rating definition and application conditions for the selected kit.
Decide whether the drawer can be reused
| Outcome | When it applies | What to do |
|---|---|---|
| Direct same-system replacement | Model/revision and all dimensional, fixing and component checks match. | Use the complete approved replacement set and its installation instructions. |
| Reuse with approved modifications | There is a documented change to blocking, fixing locations or machining, with enough sound material remaining. | Have the change reviewed before cutting or drilling. Recheck the complete envelope. |
| New drawer box or different system | Width, recess, wall thickness or structural condition cannot meet the replacement specification. | Redesign the box around an approved runner instead of forcing a near match. |
| Repair information needed first | Model or damaged component is unidentified. | Ask the original manufacturer or supplier to identify supported replacements. Do not mix rail members by appearance. |
A side-mount-to-undermount conversion is not a like-for-like replacement. It can require a new width relationship, underside recess, rear machining and front locks. Conversely, adding side rails to a box built for concealed runners can fail the side-space requirement.
Do not mix the left runner from one family with a right runner from another, or combine old drawer members with new cabinet members unless the manufacturer explicitly approves the combination.
The worksheet to send with a replacement inquiry
| Record | Measurement / photograph |
|---|---|
| Existing system | Brand ____; model ____; mounting type ____ |
| Rail and cabinet depth | Closed rail ____; usable cabinet depth ____; rear support ____ |
| Cabinet opening | Front ____; middle ____; rear ____; mounting planes identified ____ |
| Drawer box | Outside width ____; inside width ____; length ____; side thickness ____ |
| Underside details | Bottom recess ____; bottom thickness ____; rear notches / bores ____ |
| Front and locks | Inset/overlay front ____; lock model ____; fixing pattern ____ |
| Condition and intended use | Damage ____; complete drawer + contents ____ |
| Replacement approval | Exact new model ____; modifications ____; matched instructions ____ |
If several drawers look alike, check a representative of each distinct size and construction. A kitchen can contain different rail lengths, generations or drawer-box wall thicknesses.
Replacement slide families to compare
Browse the exact kit contents and the current drawer-slide collection before ordering. Neither product is represented as a universal replacement.
Soft-Close Side-Mount Slides
Compare the 10-pair side-mount family after checking closed length, side space, mounting planes and brackets.
Compare side-mount slides
Soft-Close Undermount Slide Kit
Evaluate the complete kit only after matching box dimensions, bottom recess, locks and the supplied cross-section.
Compare undermount slide kitsUse installation instructions after the compatibility check
Once the model is matched, use the undermount installation guide together with the supplied kit drawing. Its workflow is an installation resource, not proof that every existing drawer matches its measurements.
Test one properly secured drawer before converting the whole kitchen. Verify both sides seat fully, the specified locks engage, fasteners do not protrude and the drawer moves and closes as intended. Stop if it binds, releases unexpectedly or needs force to engage. Do not exceed any component rating during testing.
When fastener depth or a modified box is involved, review cabinet-joint screw-length and penetration checks. Do not copy a generic screw size into a hardware-specific mounting detail.
Frequently asked questions
Can I replace slides with the same length from another brand?
Only after checking the full envelope, mounting geometry and components. Equal nominal length does not establish a drop-in fit.
Can I keep my old undermount locking clips?
Only if the replacement manufacturer confirms compatibility with those exact clips. Similar-looking locks and rail ends are not evidence of interchangeability.
Does a 1/2-inch side-mount slide always need exactly 1/2 inch of space?
Use the required installation space and tolerance from its drawing. The physical slide thickness and the complete recommended allowance are not necessarily identical.
Should I replace one damaged rail or the pair?
Follow the original manufacturer’s supported replacement method. Do not assemble a mixed pair or mix rail members from different systems unless explicitly approved.
Product and technical references
Berta soft-close side-mount slides, undermount kit and installation guide; Accuride’s side-space guidance is linked above. Dimensions and components are product-specific; no cross-brand replacement approval or universal drawer cut size is claimed.
