drawer slides meaning of Side clearance: 1/2" + 1/32" - 0

[Andrew Pitonyak]

I purchased some KV drawer slides and they came without instructions. I believe that the side clearance is listed as:

Side clearance: 1/2" + 1/32" - 0


So, what exactly does this mean?

Assume I have an opening of 10", I don't, but it is a nice even number.

Does this mean? Does this mean that the drawer must be exactly 1 1/16" smaller than the opening (8 15/16"), or, that the drawer may be between 8 15/16" and 9", but it may NOT be larger than 9"?

[Dick Thomas]

Andrew; A clearance of 1/2" +1/32 -0 means that the clearance may be between 1/2" and 17/32"; The -0 indicates that it can NOT be less than 1/2".

Therefore with your 10" opening, your drawer width would be between 8 15/16" and 9".

[Martin Wasner]

Make the drawer between 1" and 1-1/16" less than the opening

[Dave Stuve]

These answers look good to me. Just to show you the reasoning behind their math, KV is telling you that the slide on each side of the drawer needs 1/2" with a tolerance of (+1/32, -0/32). In other words, each slide can expand 1/32 without affecting its performance, but can't shrink. So multiply that by 2 for two slides and you get a clearance of 1" and up to + 1/16, but minus 0. Given a 10" opening, the slides need 1" plus up to 1/16" so your drawer should be between 10 - 1 = 9" and 10-1-1/16 = 8 15/16.

The important concept here is that the slides can expand a little bit, but can't be compressed. (Hence the -0/32 on the tolerance.)

[Jay Aubuchon]

I have the impression that it is better to allow a little more than the minimum clearance. So, for your example, aiming for a drawer width of 8-31/32" might be good.

Those with more experience, correct me if I am wrong.

[Bradley Gray]

I would say more in summer, less in winter, here in the Mid West.

[Andrew Pitonyak]

Thanks, this really helps...

I have used drawer slides that listed a +/- tolerance, but this just had a +. WHen I used the plus, I just assumed they did not want to write 1/2+1/32 as 33/32 with zero tolerance, for example.

When I saw it this time, I thought.... that I was probably wrong. And I was.

So thanks again. Very helpful...

And yes, i am about to build another drawer that I intend to put UNDER a cabinet.

[Sam Murdoch]

I have the impression that it is better to allow a little more than the minimum clearance. So, for your example, aiming for a drawer width of 8-31/32" might be good.

Those with more experience, correct me if I am wrong.

This is risky. You would very likely end up needing thin washers between the slides and the cabinet at each screw. Tedious though workable. That 1/32" tolerance per side is really the maximum amount of play. The drawers will never work right otherwise without a fix. In my experience, at least.

[Larry Edgerton]

This is risky. You would very likely end up needing thin washers between the slides and the cabinet at each screw. Tedious though workable. That 1/32" tolerance per side is really the maximum amount of play. The drawers will never work right otherwise without a fix. In my experience, at least.

Sam

I keep a box of fender shims in the shop for just this occasion.

https://www.kimballmidwest.com/All-Products/Fleet-and-Vehicle-Maintenance/Body-and-Alignment-Shims/60433/

I buy 1/16", and the ones I bought have a pre-bent tab on the top to hang on to. You just loosen up the screw and slide one in behind and tighten the screw back up. Very unobtrusive, and as we all know, we can't be perfect all the time. The ones I use are CarQuest P.#8021634

[Sam Murdoch]

Sam

I keep a box of fender shims in the shop for just this occasion.

https://www.kimballmidwest.com/All-Products/Fleet-and-Vehicle-Maintenance/Body-and-Alignment-Shims/60433/

I buy 1/16", and the ones I bought have a pre-bent tab on the top to hang on to. You just loosen up the screw and slide one in behind and tighten the screw back up. Very unobtrusive, and as we all know, we can't be perfect all the time. The ones I use are CarQuest P.#8021634

Excellent Larry! I have used regular unobtrusive 1/2" dia. washers but your solution, with the tabs, is UPTOWN compared to my pathetic and a bit aggravating at times (though workable) solution. We all get smarter every day. AND YES - "we can't be perfect all the time". Thanks for that upgraded tip.

[Jay Aubuchon]

This is risky. You would very likely end up needing thin washers between the slides and the cabinet at each screw. Tedious though workable. That 1/32" tolerance per side is really the maximum amount of play. The drawers will never work right otherwise without a fix. In my experience, at least.

Right. For me, planning to use 1/64 of that tolerance on each side works well. If I make the drawer the maximum width, 9" in this case, I tend to end up with a fit that is too tight.

[Bruce Wrenn]

Sam

I keep a box of fender shims in the shop for just this occasion.

https://www.kimballmidwest.com/All-Products/Fleet-and-Vehicle-Maintenance/Body-and-Alignment-Shims/60433/

I buy 1/16", and the ones I bought have a pre-bent tab on the top to hang on to. You just loosen up the screw and slide one in behind and tighten the screw back up. Very unobtrusive, and as we all know, we can't be perfect all the time. The ones I use are CarQuest P.#8021634

I cut up empty cereal boxes, and use them for shims when needed. Low cost and effective.

[Ken Fitzgerald]

You can go to Woodworkers Hardware's web site and down load the instructions.

The tolerances are tight and try to make it spot on. I have, when necessary, shimmed using washers to get the needed clearances if the drawer is too small.

[Justin Ludwig]

I minus 1 1/16 always. If something happens to go haywire, I can always slide a shim in to push the cabinet guide towards the box. Some houses' walls are so out of wack around here, it's very difficult to get a cabinet installed without racking of the drawers. Shim shim shimmery.