The following are dimensional size charts for standard electric motor NEMA standard frames and configuration.
NEMA Frame Designation
D*
2E
2F
BA
H (dia.)
N Min.
U
V Min.&
Key Width
Key Thickness
Key Long
42
2 5/8
3 1/2
1 11/16
2 1/16
9/32 slot
1 1/8
3/8
--
--
3/64 flat
--
48
3
4 1/4
2 3/4
2 1/2
11/32 slot
1 1/2
1/2
--
--
3/64 flat
--
48H
3
4 1/4
4 3/4
2 1/2
11/32 slot
1 1/2
1/2
--
--
3/64 flat
--
56
3 1/2
4 7/8
3
2 3/4
11/32 slot
1 7/8@
5/8@
--
3/16@
3/16@
1 3/8@
56H
3 1/2
4 7/8
3&5@@
2 3/4
11/32 slot
1 7/8@
5/8@
--
3/16@
3/16@
1 3/8@
56HZ
3 1/2
**
**
**
**
2 1/4
7/8
2
3/16
3/16
1 3/8
66
4 1/8
5 7/8
5
3 1/8
13/32 slot
2 1/4
3/4
--
3/16
3/16
1 7/8
143T
3 1/2
5 1/2
4
2 1/4
11/32
2 1/4
7/8
2
3/16
3/16
1 3/8
145T
3 1/2
5 1/2
5
2 1/4
11/32
2 1/4
7/8
2
3/16
3/16
1 3/8
146AT
3 1/2
5 1/2
5 1/2
2 3/4
11/32
2 1/4
7/8
2
3/16
3/16
1 3/8
148AT
3 1/2
5 1/2
7
2 3/4
11/32
2 1/4
7/8
2
3/16
3/16
1 3/8
149AT
3 1/2
5 1/2
8
2 3/4
11/32
2 1/4
7/8
2
3/16
3/16
1 3/8
1412AT
3 1/2
5 1/2
11
2 3/4
11/32
2 1/4
7/8
2
3/16
3/16
1 3/8
182
4 1/2
7 1/2
4 1/2
2 3/4
13/32
2 1/4
7/8
2
3/16
3/16
1 3/8
184
4 1/2
7 1/2
5 1/2
2 3/4
13/32
2 1/4
7/8
2
3/16
3/16
1 3/8
182T
4 1/2
7 1/2
4 1/2
2 3/4
13/32
2 3/4
1 1/8
2 1/2
1/4
1/4
1 3/4
184T
4 1/2
7 1/2
5 1/2
2 3/4
13/32
2 3/4
1 1/8
2 1/2
1/4
1/4
1 3/4
182AT
4 1/2
7 1/2
4 1/2
2 3/4
13/32
2 1/4
1 1/8
2
1/4
1/4
1 3/8
L182ACY
4 1/2
7 1/2
4 1/2
2 3/4
13/32
2 1/4
7/8
2
3/16
3/16
1 3/8
182AT
4 1/2
7 1/2
4 1/2
2 3/4
13/32
2 1/4
1 1/8
2
1/4
1/4
1 3/8
186ACY
4 1/2
7 1/2
7
2 3/4
13/32
2 1/4
7/8
2
3/16
3/16
1 3/8
186AT
4 1/2
7 1/2
7
2 3/4
13/32
2 1/4
1 1/8
2
1/4
1/4
1 3/8
L186AT
4 1/2
7 1/2
7
2 3/4
13/32
2 1/4
1 1/8
2
1/4
1/4
1 3/8
189AT
4 1/2
7 1/2
10
2 3/4
13/32
2 1/4
1 1/8
2
1/4
1/4
1 3/8
203#
5
8
5 1/2
3 1/8
13/32
2 1/4
3/4
2
3/16
3/16
1 3/8
204#
5
8
6 1/2
3 1/8
13/32
2 1/4
3/4
2
3/16
3/16
1 3/8
213
5 1/4
8 1/2
5 1/2
3 1/2
13/32
3
1 1/8
2 3/4
1/4
1/4
2
215
5 1/4
8 1/2
7
3 1/2
13/32
3
1 1/8
2 3/4
1/4
1/4
2
213T
5 1/4
8 1/2
5 1/2
3 1/2
13/32
3 3/8
1 3/8
3 1/8
5/16
5/16
2 3/8
215T
5 1/4
8 1/2
7
3 1/2
13/32
3 3/8
1 3/8
3 1/8
5/16
5/16
2 3/8
219AT
5 1/4
8 1/2
11
3 1/2
13/32
2 3/4
1 3/8
2 1/2
5/16
5/16
1 3/4
2110AT
5 1/4
8 1/2
12 1/2
3 1/2
13/32
2 3/4
1 3/8
2 1/2
5/16
5/16
1 3/4
224#
5 1/2
9
6 3/4
3 1/2
13/32
3
1
2 3/4
1/4
1/4
2
225#
5 1/2
9
7 1/2
3 1/2
13/32
3
1
2 3/4
1/4
1/4
2
254#
6 1/4
10
8 1/4
4 1/4
21/32
3 3/8
1 1/8
3 1/8
1/4
1/4
2 3/8
254U
6 1/4
10
8 1/4
4 1/4
17/32
3 3/4
1 3/8
3 1/2
5/16
5/16
2 3/4
256U
6 1/4
10
10
4 1/4
17/32
3 3/4
1 3/8
3 1/2
5/16
5/16
2 3/4
254T
6 1/4
10
8 1/4
4 1/4
17/32
4
1 5/8
3 3/4
3/8
3/8
2 7/8
256T
6 1/4
10
10
4 1/4
17/32
4
1 5/8
3 3/4
3/8
3/8
2 7/8
284#
7
11
9 1/2
4 3/4
21/32
3 3/4
1 1/4
3 1/2
1/4
1/4
2 3/4
284U
7
11
9 1/2
4 3/4
17/32
4 7/8
1 5/8
4 5/8
3/8
3/8
3 3/4
286U
7
11
11
4 3/4
17/32
4 7/8
1 5/8
4 5/8
3/8
3/8
3 3/4
284T
7
11
9 1/2
4 3/4
17/32
4 5/8
1 7/8
4 3/8
1/2
1/2
3 1/4
286T
7
11
11
4 3/4
17/32
4 5/8
1 7/8
4 3/8
1/2
1/2
3 1/4
284TS
7
11
9 1/2
4 3/4
17/32
3 1/4
1 5/8
3
3/8
3/8
1 7/8
286TS
7
11
11
4 3/4
17/32
3 1/4
1 5/8
3
3/8
3/8
1 7/8
324#
8
12 1/2
10 1/2
5 1/4
21/32
4 7/8
1 5/8
4 5/8
3/8
3/8
3 3/4
326#
8
12 1/2
12 1/2
5 1/4
21/32
4 7/8
1 5/8
4 5/8
3/8
3/8
3 3/4
324U
8
12 1/2
10 1/2
5 1/4
21/32
5 5/8
1 7/8
5 3/8
1/2
1/2
4 1/4
326U
8
12 1/2
12
5 1/4
21/32
5 5/8
1 7/8
5 3/8
1/2
1/2
4 1/4
324T
8
12 1/2
10 1/2
5 1/4
21/32
5 1/4
2 1/8
5
1/2
1/2
3 7/8
326T
8
12 1/2
12
5 1/4
21/32
5 1/4
2 1/8
5
1/2
1/2
3 7/8
324TS
8
12 1/2
10 1/2
5 1/4
21/32
3 3/4$
1 7/8$
3 1/2$
1/2
1/2
2$
364#
9
14
11 1/4
5 7/8
21/32
5 5/8
1 7/8
5 3/8
1/2
1/2
4 1/4
364S#
9
14
11 1/4
5 7/8
21/32
3 1/4
1 5/8
3
3/8
3/8
1 7/8
365#
9
14
12 1/4
5 7/8
21/32
5 5/8
1 7/8
5 3/8
1/2
1/2
4 1/4
364U
9
14
11 1/4
5 7/8
21/32
6 3/8
2 1/8
6 1/8
1/2
1/2
5
365U
9
14
12 1/4
5 7/8
21/32
6 3/8
2 1/8
6 1/8
1/2
1/2
5
364T
9
14
11 1/4
5 7/8
21/32
5 7/8
2 3/8
5 7/8
5/8
5/8
4 1/4
365T
9
14
12 1/4
5 7/8
21/32
5 7/8
2 3/8
5 7/8
5/8
5/8
4 1/4
364TS
9
14
11 1/4
5 7/8
21/32
3 3/4$
1 7/8$
3 1/2$
1/2
1/2
2$
365TS
9
14
12 1/4
5 7/8
21/32
3 3/4$
1 7/8$
3 1/2$
1/2
1/2
2$
404T
10
16
12 1/4
6 5/8
13/16
7 1/4
2 7/8
7
3/4
3/4
5 5/8
405T
10
16
13 3/4
6 5/8
13/16
7 1/4
2 7/8
7
3/4
3/4
5 5/8
404TS
10
16
12 1/4
6 5/8
13/16
4 1/4$
2 1/8$
4$
1/2
1/2
2 3/4$
405TS
10
16
13 3/4
6 5/8
13/16
4 1/4$
2 1/8$
4$
1/2
1/2
2 3/4$
404U
10
16
12 1/4
6 5/8
13/16
7 1/8
2 3/8
6 7/8
5/8
5/8
5 1/2
405U
10
16
13 3/4
6 5/8
13/16
7 1/8
2 3/8
6 7/8
5/8
5/8
5 1/2
444T
11
18
14 1/2
7 1/2
13/16
8 1/2
3 3/8
8 1/4
7/8
7/8
6 7/8
445T, 447T&
11
18
16 1/2
7 1/2
13/16
8 1/2
3 3/8
8 1/4
7/8
7/8
6 7/8
444TS, 447TS&&
11
18
14 1/2
7 1/2
13/16
4 3/4$
2 3/8$
4 1/2$
5/8
5/8
3$
445TS
11
18
16 1/2
7 1/2
13/16
4 3/4$
2 3/8$
4 1/2$
5/8
5/8
3$
444U
11
18
14 1/2
7 1/2
13/16
8 5/8
2 7/8
8 3/8
3/4
3/4
7
445U
11
18
16 1/2
7 1/2
13/16
8 5/8
2 7/8
8 3/8
3/4
3/4
7
449T
11
18
25
7 1/2
13/16
8 1/2
3 3/8
8 1/4
7/8
7/8
6 7/8
449TS
11
18
25
7 1/2
13/16
4 3/4$
2 3/8$
4 1/2$
5/8
5/8
3$
* Dimension D will never be greater than the above values on rigid mount motors, but it may be less so that shims up to 1/32" thick (1/16" on 364U and 365U frames) may be required for certain machines.
@@ Motors designated 56H have two sets of 2F mounting holes--3" and 5".
$ Standard short shaft for direct-drive applications.
# Discontinued NEMA frame.
** Base of 56HZ frame motors has holes and slots to match NEMA 56, 56H, 143T and 145T mounting dimensions.
@ Certain NEMA 56Z frame motors have 1/2" x 1 1/2" long shaft with 3/64" flat. These exceptions are noted in the General Catalog.
& Dimension "V" is shaft length available for coupling, pinion or pulley hub - this is a minimum value.
