19-inch rack units and mounting ears (EIA-310) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/rack-19in-ears/  (CC BY 4.0)
Basis: EIA-310-D / IEC 60297: 19 in rack, 1U = 44.45 mm, hole spacing 15.875 / 15.875 / 12.7 mm, mounting rails 465.1 mm apart
Catalog version: 2026-10-20

Sizes: see table below
- 1U = 44.45 mm (1.75 in). Equipment height is 1U minus about 0.8 mm so panels don't bind: a 1U faceplate is 43.6 mm tall; 2U is 88.1 mm.
- Hole pattern per U: 6.35 / 22.225 / 38.1 mm from the U boundary (15.875-15.875-12.7 repeating). Rail-to-rail inside width 450.85 mm; hole centres 465.1 mm apart; faceplate width 482.6 mm (19 in).
- Cage nuts take 9.5 mm square holes (M6 or 10-32 screws); threaded rails are usually 10-32 or M6.
- Files are ear test plates with the slot pattern for 1U and 2U.

dimension  mm
1U  44.45
1U faceplate height  43.6
hole offsets within a U  6.35, 22.225, 38.1
rail hole centres (width)  465.1
inside rail width  450.85
faceplate width  482.6
cage nut square hole  9.5

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: 19-inch rack — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/19-inch_rack
- Wikipedia: Rack unit — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Rack_unit

Free files (CC BY 4.0, Xem Studio; STEP + STL, 2 parts): https://xemstudio.com/files/hardware/rack-19in-ears/index.json
API: https://xemstudio.com/api/geometry?object=rack-19in-ears