What size tolerance for inlays?

Phil, that sounds like an accuracy issue. Have you measured your bit?

I did some wood inlay and ran a couple of tests. I manually entered a bit size slightly smaller that the actual bit size until I found the sweet spot and they fit well.

*oh, using the exact same shape for the inlay and the pocket.

fudging your bit size a little smaller manually will make your inlay ever so slightly small and the pocket the same amount larger.

if they still don’t fit, your machine is distorting the shape somewhere

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instead of leaving a gap, try setting the bit size to .112 and see what that does with a quick test. Adjust the bit size as needed.

Is it something you could do with a V-Bit inlay? I would imagine the sloped sides would make it easier to get a snug fit.

Raised lettering on a floor inlay? Depending on how proud of the surface the lettering is, it sounds like a trip hazard. You can still have a bit of a raised surface with a v bit, simply make your depth of cut proportionally deeper on the inlay to what you want to protrude above the surface, plus one or two of those red frog’s hairs to allow for sanding.

Your title is “What size tolerance floor inlays?”

Dang! had me wondering what I missed (or added) there for a second!

Ok I know the voices in my head aren’t real, but sometimes they have good ideas!

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I presume your use Easel inlay app. I get very good (snug) fit using .005. Use .01 to .015 if I want a visible outline on inlay. Seems like your setting are good. Don’t see how the bit diameter would make a difference, as long as you’re using the same bit for both cuts.

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I had trouble until I went back to the recommended cut settings. I think cutting too deep and too fast gives tolerance variations in the opposite direction for the pocket versus the inlay, ie gaps in some areas, too tight in others. If I take it slow (recommended) the inlay drops right in the pocket. I also flip the inlay and cut the side going in the pocket on top using a downcut endmill. Leaves the edge nice and clean, very little hand work to get the inlay to fit.


If the bit is smaller, the inlay will be a bit bigger and the pocket will be a bit smaller. Therefore, won’t fit. Even the cheap Chinese calipers can be off enough to cause this.


Will have to think on that a bit. Using Easel inlay app, modifies both pocket and inlay parts to fit with tolerance specified. As long as cut shows no problems in preview, and you use the same bit for both, wouldn’t it cut the same difference inside and out?

any deviance larger in the bit will make the inlays loose, and smaller, too tight.


i have a spacer cut that I pull the Y to on both sides before starting a job. It’s not uncommon for it to be off a tooth or two

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But, but, but…pocket is inside cut & inlay is out side cut. Neither is on path, so what difference does it make?

Now I’m beginning to see the problem. Never had a problem so couldn’t comprehend. Guess my bits are right on size. Now that you pointed this out…I will never be able to do a good inlay again…thanks.


well, if the bit is off on the small side, it is leaving a little extra on both cuts.

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there ya go. sometimes I don’t explain well


yes, and that is on both side of the cuts, so about 1/32 off.

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