Define: 19″ Rack
Description:
The funny thing is . . . Nothing on a 19″ Rack measures 19 inches. The term 19 inch comes from the width of the front panel of the boxes that are installed in the rack (see the image below). To determine if your rack is a 19″ rack, measure the hole to hole spacing.
Rack hole-to-hole spacing:
19″ Rack = 18-5/16″ (18.312″) (465.1 mm)
23″ Rack = 22-5/16″ (22.312″) (566.7 mm)
24″ Rack = 23-5/16″ (23.312″) (592.1 mm)
More Information
- What is a Rack Unit (“U” or “RU”)
- What is EIA-310
- Wikipedia has an in-depth overview of 19″ racks.
- Why all racks are not created equal
October 10th, 2008 at 2:25 am
Why 19inch ? why not other sizes say 3.5 inch not acceptable ?
April 28th, 2009 at 8:48 am
But a SMART equipment manufacturer will make his faceplate slightly smaller than 19″ – such as 18-31/32″ to avoid any problems with rubbing in tight racks. I once had an AP Audio patch bay that actually measured 19-1/32″ and would not go into my all-steel welded rack. I e-mailed the mfg. and they said they saw no problem becuase no one else had complained before! Well, not everyone has cheap plywood racks with enough ‘give’ in the sides.
By the same token, I suppose a smart rack manufacturer would error a little on the wide side when spacing his (recessed) rails.