All the installation instructions I have seen in the past few weeks, said there is 1/16" tolerance but IDK which way.

I am guessing that is you truly have a 28 3/4" opening, you should be all right.

But I am curious what the experts will say.

I can't imagine they would ask you to cut a hole that's 28 3/4" with the object of fitting an cooktop that is exactly 28 3/4" into it. But who knows. I can't seem to find any drawings of this cooktop on line, which is frustrating.

The manual specifies a cutout width between 28 3/4 and 28 7/8 - if your cutout falls within that spec, that is what you need. That is the size it needs to be to properly fit the cooktop and is NOT the same size as the cooktop. You can find actual cooktop dimensions if you want to see the difference (I'm not going to go measure mine because crawling in the cabinet is not my idea of a good time).

If you go to Bosch's website, don't they have the manuals?

Here is one from AJ Madison.

Isn't it what you need?

Here is a link that might be useful: Manual

The cooktop is actually 31" wide.

The 28 3/4" - 28 7/8" means (to me) that you'd be OK with any width in that range. So, if you have 28 7/8", the cooktop will still be secure, but not if more than that.

If less than 28 3/4", then it won't fit. That is how read it, at least.

However, you are right to be concerned. The cabinet walls may not be exactly 5/6" to the last millimeter. If these were my cabinets and the cooktop did not fit, I'd sand down that part of the cabinet a bit and refinish by hand as it will be under the cooktop and won't be visible to anyone.

We are really taking about getting ~1/16" of an inch and I don't see why it would be a big deal. But I am pretty much new to this whole kitchen remodeling thing. :-)

I think that second dimension is for a different cooktop. The 28 3/4" is for the model I am getting the 28 7/8" is for the other 30" model (I believe it's the one that has the stainless steel edges). I actually went to Lowe's and they have one set up but it doesn't have the induction box under the glass top. However, I did measure the cutout and it was exactly 28 3/4". I am guessing the induction box is at minimum a hair smaller (I expect that wouldn't want to have a customer shoehorning it into the cabinet!) I know it's going to be a tight fit but I think it will be fine since it's my understanding that the ventilation takes place underneath the induction box and that will be an empty drawer.

I have the NIT3065UC model. The manual specifies a range for the cutout. The range is exactly the same for all three 30" models. The specified range is 28 3/4" to 28 7/8" --- As long as your cutout meets that criteria specified by the manufacturer your cooktop will:
1) Fit in the space and,
2) Be adequately supported.

All you have to do is read the manual - it is quite clear on this issue. A link to the manual is below.

Here is a link that might be useful: NIT3065UC Installation - READ PAGE 6

And the interesting thing is that the manual was already linked in my post. :-)

You don't think the first thing I did was download the manual? First, it doesn't show the dimension for the induction box. That is the dimension I am looking for. Second, the manual is for several models (the 3065 and the 5065 for the 30" models). The information in the manual does not gibe with other information I have found. See below.

This is what it says on ajmadison for the NIT3065 model:

Dimensions

Actual Width : 31"
Actual Depth : 21 1/4"
Actual Height : 4 1/8"
Cutout Width : 28 3/4"
Cutout Depth : 20"

This is what it say for the NIT5065: (The other 30" cooktop that the manual is referring to)

Dimensions

Actual Width : 31"
Actual Depth : 21 1/4"
Actual Height : 4 5/16"
Cutout Width : 28 7/8"
Cutout Depth : 19 7/8"

See how the cutout dimensions are different between the two units?

That's why I was hoping someone had the ACTUAL dimensions of the induction box.

I put an 30" 800 series in a half year ago; all I remember is that it was a very tight fit. The fastener screws and rivets were the outer extremities of the Bosch cooktop.

jerzeegirl - Seriously, just look at what the manufacturer says in their literature. ajmadison had to physically read the Bosch literature and then retype it on their site for each product, introducing a level of possible error. Perhaps the template they use only allows for one number rather than a range so they picked one. You'll notice they picked the opposite ends of the depth number as well.

If you prefer ajmadison information to Bosch information, the installation manual eleena linked from ajmadison specifies EXACTLY the same measurements.

When you are installing appliances, the appliance manufacturer's Installation Manual is the Bible - use those measurements regardless of any other measurements or numbers you may see on any other website anywhere. Period. It is their job and in their best interest to tell you what is required for installation of their appliances.

Even if you decide to purchase a larger cabinet, the hole you cut in your countertop will have to be the size specified by the manufacturer, and it will still be a tight fit - it has to be a tight fit in order to adequately support your cooktop. I don't think we can make it any clearer than that.

Now, go have a glass of wine and relax. Several months from now you'll laugh about this.

lee676: I am also considering the Bosch 800 series 30" induction cook top in an existing 30" frameless cabinet. As jerzeegirl has posted: the 5/8" sides inside the cabinet allow just enough space for the 28 3/4" cutout to fit the "box" of the 31" glass cooktop. This means the sides of the box will sit tight within the cabinet. I noted that the inside ventilation requirements for the 800 series need cutouts on the upper sides and back or bottom kickplate area of the cabinet if less than 29 1/2" width inside. If the circuitry does not cool enough, the control board will shut off the electronics (confirmed by a review post by a user whose installation did NOT have the inner ventilation slots (per pg 6: https://media3.bosch-home.com/Documents/9001410846_D.pdf) The back and left side of my island cabinet is not available to cut any ventilation slots. Did you have any of these vent slots in your cabinet, and any problems yet with your induction cooktop? I SO want to upgrade from 30" Bosch radiant (no inside ventilation requirement) to 30"

Bosch induction (same cutout requirement) ASAP. Hoping to hear your comment....