Undermount Slides Specs?

As far as I know they are all 1/2”. I’ve used Blum and Grass and they seem pretty much the same.

-- "Actions speak louder than words but not nearly as often." - Mark Twain

You need at least that much room to support the drawer bottoms no matter how thick they are, solid wood or ply.

-- Fine Custom Woodwork since 1978

Right. As long as they are no more than 1/2” I’ll be fine.
Much more than that, and with a 1/2” thick bottom, hardly any actual drawer!

ruh-roh, roy

Dang, that sucks. So in my 5 1/2” drawer opening, I’d really have 3 7/16” on the inside?

Looks like I might do wood slides after all…

I have made the recessed bottom deeper to reduce the visible gap. Don’t get too wrapped up in trying to reclaim space required by quality hardware, accept it as fact and move on. I always do the math and even do a test fit mock ups to make sure how much space to leave for the slides.
Extreme care must be taken for the case and drawers to be very square. Crooked cases and out of square drawers will be much harder to install.

-- Fine Custom Woodwork since 1978

Have you guys ever used something like this? http://ahturf.com/store/index.php?route=product/product&path=882_883_894&product_id=10399

Looks like that would allow me to build a traditional box with an integral front, tight to the opening.

Bit more money per pair and I’d only get 75lbs. capacity instead of 100.

This drawer design is killing me.

What you gain in height you loose in side clearance. Price on those Accurides seems a bit high to me, but I use KV slides for side mount. The off brand undermount slides are cheaper and harder to install with less adjustments built in, save your money and pay with time and aggravation, your choice!

-- Fine Custom Woodwork since 1978

Wdwerker, take another look. Those slides can be “flat-mounted” underneath the box.
Rated at 75lbs pair installed this way.

Probably save 1/2” in height or so, but more important, I can build an integral drawer front.

persevere with the blum tamdem runners if you can understand draw build because they are the best double extension soft close runners you can use (being a cabinet maker i have used a lot )

you dont have to rebate the bottom the half inch but if you do the runner will be wont be seen when the draw is open

Hooky

-- Happiness is a way of travel , not a destination (Roy Goodman)

You will get some sag if you flat mount those slides, I have tried it and was not happy with the results. What is the advantage to an integral drawer front? An applied front can be sized and adjusted for near perfect margins.
There are adjustments on the Blum undermount slides to level and square the drawer to the face of the opening.

-- Fine Custom Woodwork since 1978

Ok guys. I’ll get the Blum Tandems.
One more question:

From my outside face frame to inside back of cabinet is 23 1/4” (because I have a 3/4” back).

I want to inset my drawer faces. Do I get a 21” slide?
And also, since my drawer will be inset, do I still get the full extension, or really is the extension cut short the thickness of my face? Do these slides have “overtravel?”

You will have to mount the slides in from the front edge of your face frame about 7/8”. The slide will travel just a tiny bit more than the front end of the slide , so when inset mounted the back edge of the drawer will be inside your face frame. You should still have full access to the contents of the drawer. Get the template and drill bits! Install is much more accurate with them.
There are left and right locking devices that mount on the underside of the drawer box, they are sold seperatly. A depth adjustable version is available to allow you to fine tune the inset front to be perfectly flush, they cost more than the regular ones.
Wholesale the slides come in a package of 6 slides, by the time you add locking devices they cost me $168 or $28 a pair. If you can buy them in single pairs someone is breaking a box and marking them up to a higher price.
There are also heavy duty versions but I haven’t used them.
And yes, use a 21” slide I just did the math. Get your slides, build a mock up , install a set, then build your drawers.

-- Fine Custom Woodwork since 1978

• The Blums do not have over travel
• The 21” is what they make for standard 24” cabinets
• I think with an inset drawer, you will lose the thickness of your drawer front unless you notch your drawer front some so that the lever attachments are actually attached to the drawer front.

In my kitchen I have some big drawers that I’m building including one 36” wide by 30” deep. I am using 1/4” for the drawer bottom to maximize drawer space inside and then I’m using the 1/2” space in the middle of the drawer to put some reinforcement. The 1/2” depth requirement is only needed for the edges where the drawer attaches to the rails. That leaves the rest of the interior empty or in my case, I put 1/2” reinforcement at 1/4, 1/2, and 3/4 drawer width. So I get to use cheaper 1/4” ply, gain a 1/4” of interior drawer space vs 1/2” bottom, and still have a strong drawer due to reinforcement. The empty space I’m referring to is circled red in the diagram above.

Also, between the Accurides and Blum, I like the Tandems better.