Notched drawer boxes
Drawer box for the standard undermount notch: sizes, notch and hook holes
This is the page for anyone whose undermount slide is not one of the named brands on the configurator: generic or economy soft close runners, store brand slides from a cabinet retailer, and any brand whose own notch is the common 35 mm pattern. Pick “Standard Notching W/Drill” when your slide maker is not Blum, Grass, Salice, Hettich or Würth, or when you are not sure and want the pattern that fits the widest range of undermount runners.
Quick answer. A box built with Gritly’s standard undermount notch needs 5/8 in sides (1/2 in also works), an inside width of opening minus 42 mm (1 21/32 in), a length equal to your slide’s length, and a 35 mm (1 3/8 in) by 13 mm (1/2 in) rear notch with a 6 mm hook hole. We cut and drill all of it in our Las Vegas shop. This is the same back prep Blum TANDEM uses, so it also clears KV MuV+, Häfele Matrix, Hettich Quadro and most Würth PRO slides, but not Blum MOVENTO, Salice Progressa or any 3/4 in side runner.
Ready to build it? The configurator prices this option live and cuts it free.
Which slides use the standard notch?
Four generic undermount brands map straight to this option: DTC 457, GO-EZ Concealed Undermount, Astrocraf, and the LONTAN 18 in soft close runner. Beyond those, the standard notch is cut wide enough to clear several named brands’ own narrower notches too, which is why it also works as a safe default when your runner is unlisted and you do not want to use Other or unlisted slide model.
| Runner | Published notch | Clears the standard 35 mm notch? |
|---|---|---|
| KV MuV+ | 1 3/8 in (35 mm) minimum | Yes, exact match |
| Häfele Matrix UM A35 | 32 to 35 mm | Yes |
| Hardware Resources USE58 | 33 mm | Yes |
| Hettich Quadro IW21 | about 35 mm | Yes |
| Würth PRO500, PRO560, PRO600, PRO Eco | 33 mm | Yes |
| Salice Futura Smove A7555 | 33 mm notch, but a 7 mm hook hole | Notch yes; the standard 6 mm hole is undersized for Futura’s hook. Use the Futura Smove page instead. |
| Generic Amazon and store brand soft close slides | typically 1 3/8 x 1/2 in or smaller | Yes |
Several runners need their own page because their notch, hook hole or width rule is different: Blum MOVENTO (50 mm, 125 mm with TIP-ON), Salice Progressa and Progressa+ (50 mm), any push to open runner (76 to 125 mm), King Slide (46 mm per Rockler’s installation sheet), Accuride (its own width rule and hook position), and every 3/4 in side runner. If your slide is one of those, use its dedicated page instead of the standard notch.
The drawer box, dimension by dimension
This is the same back prep Blum publishes for TANDEM plus BLUMOTION 563, which is why it is the widest compatible default on the configurator. We build to the outside width you enter; the table does the subtraction for your side thickness.
| Dimension | Spec |
|---|---|
| SIDE THICKNESS | 1/2 to 5/8 in (13 to 16 mm) |
| INSIDE DRAWER WIDTH | opening minus 42 mm (1 21/32 in) |
| OUTSIDE WIDTH, 5/8 IN SIDES | opening minus 10 mm (13/32 in) |
| OUTSIDE WIDTH, 1/2 IN SIDES | opening minus 16 mm (5/8 in) |
| BOTTOM RECESS | 13 mm (1/2 in) from the bottom edge of the side to the underside of the bottom |
| BOX LENGTH | equal to your slide’s nominal length |
| MAX BOX HEIGHT | opening minus 21 mm (13/16 in); keep at least 7 mm clear above the side |
| REAR NOTCH, EACH BOTTOM CORNER | 35 mm (1 3/8 in) minimum wide, 13 mm (1/2 in) tall, flush with the side and the bottom |
| REAR HOOK HOLE | 6 mm (1/4 in) diameter, 10 mm deep, 7 mm (9/32 in) in from the inside face of the side, 11 mm (7/16 in) above the notch |
| CLIP PRE-BORE | two holes, 2.5 mm diameter, 10 mm deep at 75 degrees, 24 mm along the front and 32 mm along the side from the inside front corner |
These numbers come from Blum’s own TANDEM plus BLUMOTION documents, since the standard notch is cut to that pattern: the TANDEM plus BLUMOTION brochure. If your own slide publishes a narrower notch or a smaller hook hole, this prep still clears it; if it publishes a wider notch or a different hole size, use that model’s own page instead.
About the slides that use this notch
Slides that fit the standard notch range from name brand runners like KV MuV+ and Häfele Matrix to generic and store brand soft close slides sold under names like DTC, GO-EZ, Astrocraf and LONTAN. Most are full extension, soft close, and sold in pairs by length. Load ratings and exact lengths vary by brand: KV MuV+ is rated 75 lb (120 lb heavy duty), Häfele Matrix UM A35 about 75 lb, and generic economy runners typically do not publish an independent load figure at all. Check the number printed on your own slide or its original box rather than assuming a figure; Gritly does not publish a box load capacity for any slide.
To identify your slide, pull the drawer and read the runner screwed to the cabinet floor: the model name or a part number is usually printed near the back end. If nothing is printed, measure the notch and hook hole on your old box instead, or use how to measure and tell us the brand in your order notes.
Clips: do we install one?
No clip option is offered with Standard Notching, because the generic brands this option covers do not share one locking device part number. The front corners are still pre drilled to the same pattern Blum’s own clips use, 2.5 mm holes at 24 mm along the front and 32 mm along the side, so a Blum style clip or your slide’s own pair presses on without extra drilling. If your slide came with its own locking devices, press them on; if you know the exact brand and it has a dedicated page on this site, order from that page instead and we install the matching clip for $5.99.
Lengths and depths we build
The standard notch is available at every depth the configurator offers for a notched box, in whole inches only. Prices below are current as of October 2026.
| Depth | Extra |
|---|---|
| 9 in | included |
| 12 in | included |
| 15 in | +$7.99 |
| 18 in | +$7.99 |
| 21 in | +$7.99 |
| 24 in | +$9.99 |
| 27 in | +$12.99 |
| 30 in | +$14.99 |
A worked example
Say your cabinet opening is 24 in wide, your old box rides on an 18 in generic soft close runner, and you want 5/8 in sides. Outside width is 24 in minus 10 mm (13/32 in), which is 23 19/32 in. Depth matches the runner at 18 in. If the opening is 10 1/2 in tall and your old box cleared with room to spare, a 9 1/2 in box height keeps it well under the opening minus 13/16 in rule. Enter 23 19/32 in width, 18 in depth and 9 1/2 in height on the configurator with Notching set to “Notched & Drilled For Undermount Slides” and Slide Brand/Model set to “Standard Notching W/Drill”.
Keep your slides or replace them?
Keep them if they still glide smoothly and the drawer closes without dragging. The slide almost always outlasts a particleboard or stapled box, so a worn out drawer with a working runner usually only needs a new box built to the same notch and length. Replace the runner only if it is bent, the soft close has failed, or it no longer holds the weight you need, in which case match the new runner’s length to the depth you order.
Common mistakes
- Entering the opening instead of the outside width. We cut exactly what you type; do the subtraction first.
- Using Standard Notching for Blum MOVENTO or Salice Progressa. Both need a wider notch; use their own pages.
- Assuming a 6 mm hook hole fits every brand. Salice Futura needs 7 mm; a 6 mm hole will not seat its hook fully.
- Forgetting the depth has to equal the runner’s length exactly, not the old box depth if the runner changed.
- Picking a height too close to the opening. Leave at least 7 mm of clearance above the side.
How to order a standard notched box
1. Notching
Choose Notched & Drilled For Undermount Slides. The notch and drilling are free.
2. Slide brand and model
Choose Standard Notching W/Drill when your slide is not one of the named brands.
3. Clips
No clip option appears for this choice. Press on your slide’s own locking devices, or order from a named brand’s page if yours matches one.
4. Depth
Match your runner’s length exactly: 9 to 30 in, whole inches only.
5. Width
Enter the outside width: opening minus 13/32 in with 5/8 in sides, minus 5/8 in with 1/2 in sides.
6. Height and bottom
Stay under the opening minus 13/16 in. The bottom recess is cut to 1/2 in with either the 1/4 in or the 1/2 in bottom.
Technical sources
- Blum: TANDEM plus BLUMOTION brochure, woodworkinstitute.com. Revision: 2022.
Figures on this page were checked against these documents in October 2026. Our shop’s own rules (the 1 in side mount deduction, the cut list limits) come from how we build.
Questions
What is the standard undermount notch?
A 35 mm (1 3/8 in) by 13 mm (1/2 in) rear notch with a 6 mm hook hole, 7 mm in from the inside face of the side and 11 mm above the notch. It is the same back prep Blum publishes for TANDEM plus BLUMOTION 563, and it clears most generic and name brand undermount runners that do not have their own page.
Will the standard notch fit my Amazon or store brand soft close slides?
Almost always. Generic and store brand undermount slides typically publish a notch of 1 3/8 in or smaller and a 1/4 in hook hole, both inside the standard notch. Check your slide’s own box or listing if you are unsure.
Do I need to drill the hook hole myself?
No. The hook hole is part of the notch and drill prep and is cut in our shop before the box ships, at the position your slide expects.
How much do I subtract from the opening for the standard notch?
10 mm (13/32 in) with our standard 5/8 in sides, or 16 mm (5/8 in) with 1/2 in sides. Enter that outside width and we cut it to the 1/32 in.
Can I skip the notch and cut the back panel short instead?
Blum’s own documents describe a shortened back panel with the bottom run out to the back as an alternative to notching. We notch instead, because it keeps the bottom captured on all four sides on a dovetailed box.
What bottom recess do these slides need?
13 mm (1/2 in) from the bottom edge of the side to the underside of the bottom. Either our 1/4 in or 1/2 in bottom sits inside that recess.
Related reading
- Notched drawer boxes: every model we notch for, side by side.
- Other undermount slides: KV, Accuride, Häfele and more by name.
- Undermount drawer slide guide: the full brand comparison with manufacturer drawings.
- How to install undermount drawer slides.
Not sure of the brand? This notch covers most of them
Enter your outside width, pick the depth that matches your slide, and we cut the standard notch free. Dovetailed, cut to the 1/32 in, built in our Las Vegas shop.