STANDARD EIA OPENINGS

The EIA-310 standard defines the physical dimensions and mounting requirements for 19-inch rack enclosures used in electronics, telecommunications, and IT equipment. Established by the Electronic Industries Alliance (EIA), this standard ensures interoperability and compatibility across various equipment and manufacturers. Here are the key points of the EIA-310 standard:

  1. Rack Width: The standard specifies that the internal width of the rack should be 19 inches (482.6 mm), which is the industry standard for mounting equipment such as servers, network devices, and other hardware.
  2. Mounting Rails: EIA-310 outlines the dimensions for mounting rails, including the hole spacing for rack-mounted devices. This typically includes vertical and horizontal holes for standard 1U units (1.75-inch high) and other equipment sizes.
  3. Rack Heights: The standard supports various rack heights measured in U (rack units), with 1U being 1.75 inches tall. Common heights include 1U, 2U, 3U, and so on, allowing flexibility in equipment configuration.
  4. Mounting Depth: The standard accommodates varying depths for racks and enclosures, which allows the accommodation of different types of hardware with varying depth requirements.
  5. Environmental and Mechanical Requirements: EIA-310 also includes guidelines for things like ventilation and cable management to ensure the proper operation and longevity of the installed equipment.

In summary, EIA-310 provides a universal framework for designing and manufacturing rack enclosures that ensure compatibility and optimal performance for telecommunications and IT infrastructure.

Standard “Light Duty” Racks – EIA Openings
Rack Height Inches STD. Opening Inches “U” Factor “U” Opening Inches
20 15.63 8 14.13
21 16.63 9 15.88
22 19.63 10 17.63
23 18.63 10 17.63
24 19.63 11 19.38
25 20.63 11 19.38
26 21.63 12 21.13
27 22.63 12 21.13
28 23.63 13 22.88
29 24.63 14 24.63
30 25.63 14 24.13
31 26.63 15 26.38
32 27.63 15 26.38
33 28.63 16 28.13
34 21.63 16 21.13
35 30.63 17 29.88
36 32.63 18 31.13
37 21.63 12 21.13
38 33.63 19 33.38
39 34.63 19 33.38
40 35.63 20 35.13
41 36.63 20 35.13
42 37.63 21 36.88
43 39.63 22 38.63
44 21.63 12 21.13
45 40.38 23 40.38
46 40.63 23 40.38
47 42.63 24 42.13
48 43.63 24 43.88
49 44.63 25 43.88
50 45.63 26 45.63
51 46.63 26 45.63
52 47.63 26 45.63
53 47.63 27 47.38
54 49.63 28 49.13
55 50.63 28 49.13
56 51.63 29 50.88
57 52.63 30 52.63
58 53.63 30 52.63
59 54.63 31 54.38
60 21.63 31 54.38
61 56.63 32 54.38
62 57.63 32 56.13
63 58.63 33 57.88
64 59.63 34 59.63
65 60.63 34 59.63
66 61.63 35 61.38
67 62.63 35 61.38
68 63.63 36 63.13
69 64.63 36 63.13
70 65.63 37 64.88
71 66.63 38 66.63
72 67.63 38 66.63
73 68.63 39 68.38
74 69.63 39 68.38
75 70.63 40 70.13
76 71.63 40 70.13
77 72.63 41 71.88
78 73.63 42 71.88
79 74.63 42 73.63
80 75.63 43 75.38
Standard “Medium Duty” Racks – EIA Openings
Rack Height Inches STD. Opening Inches “U” Factor “U” Opening Inches
20 14.56 8 14.13
21 15.56 8 14.13
22 16.56 9 15.88
23 17.56 10 17.63
24 18.56 10 17.63
25 19.56 11 19.38
26 20.56 11 19.38
27 21.56 12 21.13
28 22.56 12 22.13
29 23.56 13 22.88
30 24.56 14 24.63
31 25.56 14 24.63
32 26.56 15 26.38
33 27.56 15 26.38
34 28.56 16 28.13
35 29.56 16 28.13
36 30.56 17 29.88
37 31.56 18 31.63
38 32.56 18 31.63
39 33.56 19 33.38
40 34.56 19 33.38
41 35.56 20 35.13
42 36.56 20 35.13
43 37.56 21 36.88
44 38.56 22 38.63
45 39.56 22 38.63
46 40.56 23 40.38
47 41.56 23 40.13
48 42.56 24 42.13
49 43.56 24 42.13
50 44.56 25 43.88
51 45.56 26 45.63
52 46.56 26 45.63
53 47.56 27 47.38
54 48.56 27 47.38
55 49.56 28 49.13
56 50.56 28 49.13
57 51.56 29 50.88
58 52.56 30 52.63
59 53.56 30 52.63
60 54.56 31 54.38
61 55.56 31 54.38
62 56.56 32 56.13
63 57.56 32 56.13
64 58.56 33 57.88
65 59.56 34 59.63
66 60.56 34 59.63
67 61.56 35 61.38
68 62.56 35 61.38
69 63.56 36 63.13
70 64.56 36 63.13
71 65.56 37 64.88
72 66.56 38 66.63
73 67.56 38 66.63
74 68.56 39 68.38
75 69.56 39 68.38
76 70.56 40 70.13
77 71.56 40 70.13
78 72.56 41 71.88
79 73.56 42 73.63
Standard “Heavy Duty” Racks – EIA Openings
Rack Height Inches STD. Opening Inches “U” Factor “U” Opening Inches
20 15.88 9 15.88
21 16.88 9 15.88
22 17.88 10 17.63
23 18.88 10 17.63
24 19.88 11 19.38
25 20.88 11 19.38
26 21.88 12 21.13
27 22.88 13 22.88
28 23.88 13 22.88
29 24.88 14 24.63
30 25.88 14 24.63
31 26.88 15 26.38
32 27.88 15 26.38
33 28.88 16 28.13
34 29.88 17 29.88
35 30.88 17 29.88
36 31.88 18 31.63
37 32.88 18 31.63
38 33.88 19 33.38
39 34.88 19 33.38
40 35.88 20 35.13
41 36.88 21 36.88
42 37.88 21 36.88
43 38.88 22 38.63
44 39.88 22 38.63
45 40.88 23 40.38
46 41.88 23 40.38
47 42.88 24 42.13
48 43.88 25 43.88
49 44.88 25 43.88
50 45.88 26 45.63
51 46.88 26 45.63
52 47.88 27 47.38
53 48.88 27 47.38
54 49.88 28 49.13
55 50.88 29 50.88
56 51.88 29 50.88
57 52.88 30 52.63
58 53.88 30 52.63
59 54.88 31 54.38
60 55.88 31 54.88
61 56.88 32 56.13
62 57.88 33 57.88
63 58.88 33 57.88
64 59.88 34 59.63
65 60.88 34 59.63
66 61.88 35 61.38
67 62.88 35 61.38
68 63.88 36 63.13
69 64.88 37 64.88
70 65.88 37 64.88
71 66.88 38 66.63
72 67.88 38 66.63
73 68.88 39 68.38
74 69.88 39 68.38
75 70.88 40 70.13
76 71.88 41 71.88
77 72.88 41 71.88
78 73.88 42 73.63
79 74.88 42 73.63
80 75.88 43 75.38

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