Pre-Drilled Shelf Hole Spacing for Bookcases

When customers don't know where they really want the shelves, it's time to fire up the line boring machine. March 25, 2007

What is the typical hole spacing for shelving in tall bookcases and entertainment centers? I used to drill holes every inch from about 6" from the bottom and top. Besides looking like a pre-drilled panel, I thought this looked like crap and took hours to drill (using a jig and drill). Now I equally divide the shelving and drill 4 - 6 holes above and below that shelf position, usually 2" apart. I just installed a built-in and he called be back a day later and said he needs more holes due to the books' height. I am looking for a way to avoid this situation in the future and not have to drill thousands of useless holes.

Forum Responses
(Cabinetmaking Forum)
From contributor P:
At the risk of making this sound simple, why not just ask the customer what they'll use the cabinet for and where they would like to be able to put shelves?

From contributor D:
5 mm holes at a 32 mm spacing.

From contributor B:
Add up all the time you spend drilling holes each year and figure out how much that time is worth. Then find a new or used Delta or other line boring machine and either use all your newly freed up time to take more breaks or make more money. It will also speed your hardware installation.

From contributor R:
I understand what you mean about all the holes not looking good. How about using slightly recessed shelf standards in antique bronze (or whatever is compatible with the finish color)? I think you'd get a uniform finished look that way and full adjustability.

From the original questioner:
Pretty much what you get when you ask is indecisiveness, which leads to lot of holes. I agree on the line boring machine, although currently there's a wish list of machines to make my life easier. My budget and shop size limits me from buying every dedicated tool out there. So for right now, it's a quick jig and time spent drilling. But back to the spacing… When line boring holes, are you filling up the panel or is there some reasoning behind the spacing?

From contributor J:
If system holes aren't your thing ("they look predrilled," and you indicate that "they look like crap"), why not go with fixed shelves or KV shelf standards? A 2" OC machine can be had if you do not wish to utilize system holes, and is faster and more accurate and could spare you the constant pain in the butt of guessing where the builder or customer can dream up to put the shelves.

From contributor D:
I typically drill 5 holes for each shelf, though there are times when that is not enough, as in your current case. I am going to make changes to my system to start drilling balanced panels with holes up and down both sides.

From contributor E:
Not to beat a dead horse, but I second the recommendation for a line boring machine; it really is a must if you're doing cabinetry, as almost everything you do will need shelves. And a cheaper unit will pay for itself with one or two jobs.

Having said that, I just use common sense when spacing holes. Nothing drilled less than roughly eight inches off the bottom of a cabinet and nothing drilled closer than six inches to the top for kitchens. Bookshelves you could probably leave a little more room; entertainment centers a little less. It's more important to communicate with the client on these types of projects as to what they require.

As to the spacing between holes, the standard is 32mm, so I would stick to that. There's usually a practical reason things become standard. When you try to reinvent the wheel and vary these, you generally find out the hard way why they are standard. I have made custom templates for alternate spacing (like 2") when clients specifically asked for it. I don't like doing custom hole spacing, though, as I have a lot invested in my line boring machine.

From contributor J:
I've never had a single customer complain or even make comment on the number of holes. Now if I were to ask them for their input, creating a problem where there isn't one, they would probably first be unaware of what exactly I was talking about, and second unable to make an informed decision about where to put the holes… That's why they hired me - to know. I hit every panel the full lick, 32mm oc, then there's no question where they can put the shelves. Put them anywhere! I think a lot of your troubles stem from A - Not having a line boring machine; and B - As a result of A, trying to get the customer to give you an exact shelf placement (like they have nothing else on their minds about the time you're starting their cabinets) so that you can drill as few holes as possible, because you're expending a lot of labor drilling them by hand. I'll guarantee you that after hand drilling about 20 holes with a 29.00 hand drill and a 4.00 piece of pegboard, they wouldn't look good to me either. Bottom line if this isn't your last job, get yourself a boring machine.