Of weirdo 23″ Telecom vs 19″ computer racks and things

Ok, if you are unlucky enough you might have an older 23″ telecom rack. The annoying thing is that most computer components these days are 19″ wide.


What’s all this then about 19″ racks? As an aside, it’s hard to believe we are using a 100 years standard set by AT&T in 1922 for racks also known as EIA-310 racks. These were for telephone relays and the geniuses back then made the racks 19 ½ inches from center to center. With a height in multiples of 1 ¾ inches. Then in 1934, we got the standard screw which is 12-24 (UTS Standard) where 12 is the size and it is 24 threads per inch.

And these days there are a zillion bolt standards (OK there are really three, there is 12-24, 10-20 and M6) so the modern racks, use cage nuts that you stick into big holes so you can use any of these).


But what if you have an older system. For a long time we’ve had a wider rack and nothing would quite fit. It was so mysterious what this was. But thanks to a new buddy Tom, he explained it to me. There is another standard called the telecom rack also known as an EIA rack or the Westinghouse EIA rack that is 23″ wide and on one-inch centers such as those made by Chatsworth. If you have one of these racks, then standard computer equipment won’t fit. So you need some spacers to make that happen see below.

Finding 23 to 19 reducers and shelves

Of course, someone has solved just about every problem and Rack Solutions makes a 23 (or 24″ there are those racks too) reducers. These are recessed, so that you get all your 19″ equipment in the proper alignment and not sticking out (that’s a technical term).

And given this, if you are short shelves, its pretty hard to find 23″ shelves these days, so Rack Solutions has a few solutions there as well.

Note that one thing to figure out is if you have a so called 2-post or 4-post rack. Most racks, are two post that are either front mounted or in the center. The idea of the front mount is that all the weight of the equipment is cantilevered over the front and then it is easy to pull out. You don’t need to get to the back of the rack to unscrew things. Alternatively, you can get rails that pull out so that you can access the equipment.

Add this to some cage nuts, some bolts for the EIA 23″ rack and you are set. I could spend my life at Rack Solutions buying stuff like this from open cage racks to closed ones, they are a great solution to tidy everything from home theater equipment to server rooms. 🙂

I’m Rich & Co.

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