Hettich drawer slide question.

[Ken Krawford]

I’m installing some Quardo IW21 drawer slides. I’m using 5/8” material for the drawer box. My understanding is that the width of the drawer should be 5/8” less than the drawer opening and the length should be 21”. Is that correct?
The supplier mistakenly send locking clips for 1/2” stock. Can I use them or will this be a problem?

[Jeff Roltgen]

What you get with Quadro's for front mounting clips are for 5/8" stock. For current 4D clips, you should have received Hettich part # 921897901.
In 15 years of use, it's always been the same clip, whether it's 5/8 or 1/2" stock.

Drawer box opening -3/8" will give you 3/16" gap either side since you are using 5/8" stock. Hopefully you haven't constructed boxes yet using the 5/8 subtraction. If so, only fix is to add 1/8" shims behind drawer slides to push them out from each side, allowing them to fit, yet stay centered in your openings.

The small 1/8" filler/spacer shims are included to make up the difference at back edge of drawer front if you are using 1/2" stock instead of 5/8, but this is in reference to pushing the clip 1/8" further back into drawer opening in cabinet due to thinner material. No adaptors available from Hettich for width, as you simply must use the proper formula to arrive at proper drawer width.

jeff

[Ken Krawford]

Jeff, thanks so much for your feedback. No, I haven't started building yet thank goodness. My invoice shows part # H.9140416 Front fixing clip set for 1/2" drawer box. Since this is a different part number than you referenced do you think it will still work?
I'll make the 3/8" correction on the width. Is a 21" overall length ok?
I've always used Blum before so these are just a bit different.

[Jeff Roltgen]

Ken- Interesting they specify "for 1/2" drawer box" - just looked up that part # - showed up at CSHardware in my search. Sure enough- those definitely look thicker at the base in the image= will probably push your drawers out an extra 1/8". Check with your supplier- way handier to have the regular clips for your 5/8 stock. Or, in a pinch, you may have to drill your mounting holes in cab sides an 1/8 further into cabinet for it to work out. (Ugh!) I guess this must be why my local wholesaler carries the universal clip-sets.

21" length is my target, +/- a fraction. The Quadro 4D's are very forgiving, especially with that spring-loaded rear clip on the slide. Really like this upgraded version for all it's adjustability - saves a lot of tweaking at installation time, so I feel the extra $ over the standard V-6 pays for itself.

My supplier has been strictly Hettich for decades, so if I try Blum's, I'll have to ask you for guidance!

Good luck!

[Ken Krawford]

Jeff, sorry to beat this to death but I want to do this correctly. The linked Hettich image shows a 7/16" distance between the bottom edge of the drawer bottom and the center of the 1/2" drill hole on the drawer back. It doesn't specify but it appears that in the drawing the drawer bottom is 1/4". Since these drawers are going to carry a fairly heavy load, I'm using 1/2" drawer bottoms. This means that drill hole will go through both the drawer bottom and the drawer back. That seems a bit ugly. Am I reading this right? Is there a work around?
Thanks again for your generous help.
https://i.postimg.cc/kGmbs6HW/Screen-Shot-2021-06-13-at-5-53-42-PM.png

[Dave Sabo]

You realize the depth of the holes is only 3/8” , right ?

[Ken Krawford]

Yes I do. It's not the depth of the hole that concerns me. It's the vertical distance relative to the drawer bottom. The linked drawing shows the center of the hole 7/16" from the bottom edge of the drawer bottom. The drawer bottom is 1/2" thick and the hole being drilled is 1/4" diameter so it will span the junction between the drawer bottom and the back of the drawer box. Put another way, the 1/4" (4/16") hole will be 1/16" into the drawer bottom and 3/16" into the drawer back.

You realize the depth of the holes is only 3/8” , right ?

[Jamie Buxton]

Yes I do. It's not the depth of the hole that concerns me. It's the vertical distance relative to the drawer bottom. The linked drawing shows the center of the hole 7/16" from the bottom edge of the drawer bottom. The drawer bottom is 1/2" thick and the hole being drilled is 1/4" diameter so it will span the junction between the drawer bottom and the back of the drawer box. Put another way, the 1/4" (4/16") hole will be 1/16" into the drawer bottom and 3/16" into the drawer back.

One fix to your dilemma is to make the drawer bottom with two layers of 1/4" plywood. It is one layer thick around the edges, and two layers thick in the middle. In particular, it is one layer at the front and sides. The dados in the sides and front are the same as if the bottom is just one layer of plywood. The hole in back for the slide's hook is the same as if the drawer bottom is 1/4". But except for the edges the drawer bottom is 1/2" thick.

[Ken Krawford]

Jamie you pose an interesting solution but I've already bought the 1/2" baltic birch ply for the bottoms and at current prices I'd rather it not sit unused in my rack.