Blum slide And Drawer Box Sizing

[Ken Krawford]

With side mounted slides it's so easy - drawer opening minus 1" = drawer box width.
I'm installing some 21" Blum 563 undermount slides. My drawer opening is 15" and I'm using 5/8" stock for the drawer boxes. I've calculated a drawer width of 14 5/8". Am I ok so far?
The slides are 21" and Blum says the drawer length should be 18" but when I measure the slide/clip assembly it appears my drawer should be 21 1/2" long overall with 5/8" stock. Which number is right?
Thanks in advance.

[George Bokros]

Blum has all the information you need on their website.

Link http://www.blum.com/us/en/index.php/

I have used their slides and used the info they provide on their website and it has worked perfectly




(http://www.blum.com/us/en/index.php/)

[Jamie Buxton]

With side mounted slides it's so easy - drawer opening minus 1" = drawer box width.
I'm installing some 21" Blum 563 undermount slides. My drawer opening is 15" and I'm using 5/8" stock for the drawer boxes. I've calculated a drawer width of 14 5/8". Am I ok so far?
The slides are 21" and Blum says the drawer length should be 18" but when I measure the slide/clip assembly it appears my drawer should be 21 1/2" long overall with 5/8" stock. Which number is right?
Thanks in advance.

Yes, your outside width should be 14 5/8".
But your depth doesn't seem right. If you have what Blum calls 21" slides, the outside front-to-back dimension should be 21".

[Peter Quinn]

You have the width correct. Once you work through their "from inside of drawer box" formula....the bass akwards enginer method I like to call it....because nobody builds drawers from the inside out....basically you subtract 3/8" from the opening for 5/8" drawer boxes and subtract 5/8" from the opening for 1/2" drawer boxes. The height is pretty clear in their pictograms. Something is amiss with your lengths. If you are after 21" drawer boxes and the correct slides are 563h5330 or 563.5330 (tel:563.5330), they are not exactly 21" long, don't let that bother you. For 18" boxes you need the 563.457 series, I think the H is soft close? The clear space requires interior is roughly 1" longer than the given drawer box, and the slides start from the BACK of the front of the drawer, so slide length and drawer box are not equivalent, just vaguely related. If you stare at the Blum guide long enough you will either understand it or go crazy, or both!

[Ken Krawford]

You have the width correct. Once you work through their "from inside of drawer box" formula....the bass akwards enginer method I like to call it....because nobody builds drawers from the inside out....basically you subtract 3/8" from the opening for 5/8" drawer boxes and subtract 5/8" from the opening for 1/2" drawer boxes. The height is pretty clear in their pictograms. Something is amiss with your lengths. If you are after 21" drawer boxes and the correct slides are 563h5330 or 563.5330 (tel:563.5330), they are not exactly 21" long, don't let that bother you. For 18" boxes you need the 563.457 series, I think the H is soft close? The clear space requires interior is roughly 1" longer than the given drawer box, and the slides start from the BACK of the front of the drawer, so slide length and drawer box are not equivalent, just vaguely related. If you stare at the Blum guide long enough you will either understand it or go crazy, or both!

Peter, I'm still in the "go crazy" phase. If I measure the slide from the "hook" at the back that goes into the back of the drawer box to the clip that attaches to the "back of the drawer front" my measurement is 20 9/16" . Their literature show an 18" drawer length for a 21" slide. I'm using a B563H5330B slide. I can't get my head around the 2 9/16" difference. I know my numbers are wrong but I can't seem to figure out where.

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[Steve Jenkins]

If you have a 21" slide make your box 21". Looking at your pic the front of the box will be right where the 21 is on your rule.

[Jamie Buxton]

... Their literature show an 18" drawer length for a 21" slide...
You've got to be reading it wrong. A 21" slide takes a 21" box.

[Ken Krawford]

You've got to be reading it wrong. A 21" slide takes a 21" box.

You, Peter and Steve are absolutely correct. I must have looked at that chart 20 times and still managed to misread it.
Thanks to all who responded.

[Peter Quinn]

The 533's are 533MM, which is 21". The chart is as confusing as I imagine it could be. Its baffling to me why they have not made some attempt to improve it....perhaps they prefer to keep these things in the hands of professionals? Maybe a subtle way of limiting access? Lots of numbers on the chart, you need to tune out all the largely irrelevant numbers, and focus on the drawer length. I have gotten a handle on that chart and un-gotten it a number of times, don't feel at all bad. Once you realize the slide numbers correspond to the metric number for the drawer length, and you convert them to inches, it may all start to make sense.

I know we get a lot of flack in the ether as Americans for still being on the SAE system, but is it any coincidence that the slides fall on 9", 12", 15", 18", 21" and 24" almost perfectly? Those are some pretty weird metric numbers, not nice and even like some metric things. They could certainly just print (21" drawer slides") right on the darn things....but they keep pushing the metric system on us, and we keep resisting.

Glad you have this worked out....picking the correct hinges and plates for your application is even more special! Something to look forward to!