Motor Frame Size Chart
Quick Reference NEMA Dimensions
Need to identify or cross-reference motor frame sizes? Our motor frame size chart simplifies the process with clear, standard dimensions. Whether you're replacing a motor or designing a new system, use this chart to ensure accurate fit and compatibility.
The dimensions listed here are intended for reference purposes only. Dimensions shown in the shaded areas will not change from one brand to another for motors built to NEMA rigid base or C-face mounted dimensional standards. Other dimensions shown are determined by the manufacturer rather than NEMA standards. Those listed are for LEESON® and Century® and may differ from other brands.
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Understanding NEMA Motor Frame Sizes
Frame size can tell you physical dimensions and mounting configuration for NEMA motors. Frame size can also help you understand cooling options and overall performance. When buying a motor, make sure your selection fits within your available space and can be mounted securely.
NEMA (the National Electrical Manufacturers Association) sets standards for the dimensions of frame sizes. Most electric motor manufacturers build their motors to meet these standards.
Rigid and Resilient Mount Motors
C-Face Motors
XO denotes clearance for the capacitors of single phase motors through the 215T frame. On three phase 254T frame and large motors, T denotes clearance for the lifting eyebolt.
The overall length (“C” dimension) will change with the enclosure, horsepower, and speed for the same brand. This will vary from one brand to another for motors of the same HP, speed or enclosure.
NEMA C face motors with a rigid base have different BA dimensions in the following instances:
-
143TC & 145TC – 2 3/4” instead of 2 1/4”
-
182TC & 184TC – 3 1/2” instead of 2 3/4”
-
213TC & 215TC – 4 1/4” instead of 3 1/2”
-
254TC & 256TC – 4 3/4” instead of 4 1/4”
Beware of NEMA frame suffix letters other than those listed above as they denote different mounting or shaft dimensions.
For example, suffix letter Y denotes special mounting provisions and Z denotes special shaft dimensions (as in 184TYZ for example). Motors having no suffix letters (other than NEMA frames 42, 48 and 56) are built to prior NEMA standards. Prefix letters are often used by manufacturers (as in G184T) to indicate the overall length of a motor but do not denote differences in the NEMA standardized mounting dimensions.
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NEMA T FRAME DIMENSIONS
The following NEMA chart outlines the NEMA series and frame size dimensions.
| Nema Series |
D | E | F | H | N | O | P | U | N-W | AA Size |
AB | AH | AJ | AK | BA* | BB | BD | XO/T^ | XP | Tap | Key Size sq. |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 42 | 2 5/8 | 1 3/4 | 27/32 | 9/32 Slot |
1 1/4 | 5 1/16 | 4 7/8 | 3/8 | 1 1/8 | 3/8 | 4.5 | 1 5/16 | 3 3/4 | 3 | 2 1/6 | 1/8 | 4 7/8 | 1 5/8 | 5 1/8 | 1/4-20(4) | 3/64 Flat |
| 48 | 3 | 2.125 | 1 3/8 | 11/32 Slot |
1 5/8 | 5 7/8 | 5 5/8 | 1/2 | 1 1/2 | 1/2 | 4 7/8 | 1 11/16 | 3 3/4 | 3 | 2 1/2 | 1/8 | 5 | 2 1/4 | 5 7/8 | 1/4-20(4) | 3/64 Flat |
| 56 56H |
3 1/2 | 2 7/16 | 1 1/2 2 1/2 |
11/32 Slot |
2 | 6 7/8 | 6 5/8 | 5/8 | 1 7/8 | 1/2 | 5 3/8 | 2 1/16 | 5 7/8 | 4 1/2 | 2 3/4 | 1/8 | 6 1/2 | 2 1/4 | 7 1/4 | 3/8-16(4) | 3/16 |
| 143T 145T |
3 1/2 | 2 3/4 | 2 2 1/2 |
11/32 | 2 3/8 | 6 7/8 | 6 5/8 | 7/8 | 2 1/4 | 3/4 | 6 3/8 | 2 1/8 | 5 7/8 | 4 1/2 | 2 1/4* | 1/8 | 6 1/2 | 2 1/4 | 7 1/4 | 3/8-16(4) | 3/16 |
| 182T 184T |
4 1/2 | 3 3/4 | 2 1/4 2 3/4 |
13/32 | − | 8 3/4 | 8 1/2 | 1 1/8 | 2 3/4 | 3/4 | 6 3/8 | 2 5/8 | 7 1/4 | 8 1/2 | 2 3/4* | 1/4 | 8 7/8 | 2 1/2 | 9 1/8 | 1/2-13(4) | 1/4 |
| 213T 215T |
5 1/4 | 4 1/4 | 2 3/4 3 1/2 |
13/32 | − | 10 5/8 | 9 3/4 | 1 3/8 | 3 3/8 | 3/4 | 8 3/8 | 3 1/8 | 7 1/4 | 8 1/2 | 3 1/2* | 1/4 | 9 | 1 3/4 | 10 3/4 | 1/2-13(4) | 5/16 |
| 254T 256T |
6 1/4 | 5 | 4 1/8 5 |
17/32 | − | 13 | 13 | 1 5/8 | 4 | 1 1/4 | 10 1/2 | 3 3/4 | 7 1/4 | 8 1/2 | 4 1/2* | 1/4 | 10 | 2 1/4 | 13 | 1/2-13(4) | 3/8 |
| 284T 284TS |
7 | 5 1/2 | 4 3/4 | 17/32 | − | 14 1/2 | 13 3/8 | 1 7/8 1 5/8 |
4 5/8 3 1/4 |
1 1/2 | 11 7/8 | 4 3/8 3 |
9 | 10 1/2 | 4 3/4 | 1/4 | 11 1/4 | 2 1/4 | 14 1/2 | 1/2-13(4) | 1/2 3/8 |
| 286T 286TS |
5 1/2 | − | 1 7/8 1 5/8 |
4 5/8 3 1/4 |
4 3/8 3 |
1/2 3/8 |
|||||||||||||||
| 324T 324TS |
8 | 6 1/4 | 5 1/4 | 21/32 | − | 16 1/8 | 15 7/8 | 2 1/8 1 7/8 |
5 1/4 3 3/4 |
2 | 13 | 5 3 1/2 |
11 | 12 1/2 | 5 1/4 | 1/4 | 14 | 2 5/8 | 16 1/8 | 5/8-11(4) | 5/8 1/2 |
| 326T 326TS |
6 | 2 1/8 1 7/8 |
5 1/4 3 3/4 |
5 3 1/2 |
5/8 1/2 |
||||||||||||||||
| 364T 364TS |
9 | 7 | 5 5/8 | 21/32 | − | 18 3/8 | 17 7/8 | 2 3/8 1 7/8 |
5 7/8 3 3/4 |
3 | 14 | 5 5/8 3 1/2 |
11 | 12 1/2 | 5 7/8 | 1/4 | 14 | 2 5/8 | 18 3/8 | 5/8-11(8) | 5/8 1/2 |
| 365T 365TS |
6 1/8 | 2 3/8 1 7/8 |
5 7/8 3 3/4 |
5 5/8 3 1/2 |
5/8 1/2 |
||||||||||||||||
| 404T 404TS |
10 | 8 | 6 1/8 | 13/16 | − | 20 | 19 5/8 | 2 7/8 2 1/8 |
7 1/4 4 1/4 |
3 | 16 | 7 4 |
11 | 12 1/2 | 6 5/8 | 1/4 | 14 | 2 5/8 | 20 | 5/8-11(8) | 3/4 1/2 |
| 405T 405TS |
6 7/8 | 2 7/8 2 1/8 |
7 1/4 4 1/4 |
7 4 |
3/4 1/2 |
||||||||||||||||
| 444T 444TS |
11 | 9 | 7 1/4 7 1/4 |
13/16 | − | 21 3/4 21 3/4 |
21 3/8 21 3/8 |
3 3/8 2 3/8 |
8 1/2 4 3/4 |
3 | 20 | 8 1/4 4 1/2 |
14 | 16 | 7 1/2 | 1/4 | 18 | 3 3 |
21 1/2 21 1/2 |
5/8-11(8) | 7/8 5/8 |
| 445T 445TS |
8 1/4 8 1/4 |
21 3/4 21 3/4 |
21 3/8 21 3/8 |
3 3/8 2 3/8 |
8 1/2 4 3/4 |
8 1/4 4 1/2 |
3 3 |
21 1/2 21 1/2 |
7/8 5/8 |
||||||||||||
| 447T 447TS |
10 10 |
23 23 |
22 3/4 22 3/4 |
3 3/8 2 3/8 |
8 1/2 4 3/4 |
8 1/4 4 1/2 |
3 1/4 3 1/4 |
24 24 |
7/8 5/8 |
||||||||||||
| 449T 449TS |
12 1/2 12 1/2 |
23 23 |
23 3/8 23 3/8 |
3 3/8 2 3/8 |
8 1/2 4 3/4 |
8 1/4 4 1/2 |
3 1/4 3 1/4 |
24 24 |
7/8 5/8 |
PRIOR NEMA FRAME MTG DIMENSIONS
| D | E | F | H | U | BA | N-W | Key | |
|---|---|---|---|---|---|---|---|---|
| 66 | 4 1/8 | 2 15/16 | 2 1/2 | 13/32 | 3/4 | 3 1/8 | 2 1/4 | 3/16 |
| 143 145 |
3 1/2 | 2 3/4 | 2 2 1/2 |
11/32 | 3/4 | 2 1/4 | 2 | 3/16 |
| 182 184 |
4 1/2 | 3 3/4 | 2 1/4 2 3/4 |
13/32 | 7/8 | 2 3/4 | 2 1/4 | 3/16 |
| 203 204 |
5 | 4 | 2 3/4 3 1/4 |
13/32 | 3/4 | 3 1/8 | 2 1/4 | 3/16 |
| 213 215 |
5 1/4 | 4 1/4 | 2 3/4 3 1/2 |
13/32 | 1 1/8 | 3 1/2 | 3 | 1/4 |
| 224 225 |
5 1/2 | 4 1/2 | 3 3/8 3 3/4 |
13/32 | 1 | 3 1/2 | 3 | 1/4 |
| 254 254U 256U |
6 1/4 | 5 | 4 1/8 | 17/32 | 1 1/8 | 4 1/4 | 3 3/8 | 1/4 |
| 5 | 1 3/8 | 3 3/4 | 5/16 | |||||
| 284 284U 286U |
7 | 5 1/2 | 4 3/4 | 17/32 | 1 1/4 | 4 3/4 | 3 3/4 | 1/4 |
| 5 1/2 | 1 5/8 | 4 7/8 | 3/8 | |||||
| 324 324U 326 326U |
8 | 6 1/4 | 5 1/4 | 21/32 | 1 5/8 1 7/8 1 5/8 1 7/8 |
5 1/4 | 4 7/8 5 5/8 4 7/8 5 5/8 |
3/8 1/2 3/8 1/2 |
| 6 | ||||||||
| 364 364U 365 365U |
9 | 7 | 5 5/8 | 21/32 | 1 7/8 2 1/8 1 7/8 2 1/8 |
5 7/8 | 5 5/8 6 3/8 5 5/8 6 3/8 |
1/2 |
| 6 1/8 | ||||||||
| 404 404U 405 405U |
10 | 8 | 6 1/8 | 13/16 | 2 1/8 2 3/8 2 1/8 2 3/8 |
6 5/8 | 6 3/8 7 1/8 6 3/8 7 1/8 |
1/2 5/8 1/2 5/8 |
| 6 7/8 | ||||||||
| 444 444U 445 445U |
11 | 9 | 7 1/4 | 13/16 | 2 3/8 2 7/8 2 3/8 2 7/8 |
7 1/2 | 7 1/8 8 5/8 7 1/8 8 5/8 |
5/8 3/4 5/8 3/4 |
| 8 1/4 | ||||||||
| 504U 505 |
12 1/2 | 10 | 8 9 |
15/16 | 2 7/8 | 8 1/2 | 8 5/8 | 3/4 |
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IEC & NEMA COMPARISON
| DIMENSION IN MILLIMETERS | KW/HP~ FRAME ASSIGNMENTS 3 Phase-TEFC |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| ICE | NEMA | D | E | F | H | U | BA | N-W | 2 Pole | 4 Pole | 6 Pole |
| 56 | NA | 56 - |
45 - |
35.5 - |
5.8 - |
9 - |
36 - |
20 - |
- - |
- - |
- - |
| 63 | NA | 63 - |
50 - |
40 - |
7 - |
11 - |
23 - |
.25KW 1/3HP |
.18KW 1/4HP |
- - |
- - |
| 71 | 42 | 71 66.7 |
56 44.5 |
45 21.4 |
7 7.1 |
14 9.5 |
45 52.4 |
30 - |
.55 3/4 |
.37 1/2 |
- - |
| 80 | 48 | 80 76.2 |
62.5 54 |
50 34.9 |
10 8.7 |
19 12.7 |
50 63.5 |
40 38.1 |
1.1 1-1/2 |
.75 1 |
.55KW 3/4HP |
| 90S | 56 | 90 88.9 |
70 61.9 |
50 38.1 |
10 8.7 |
24 15.9 |
56 69.9 |
50 46.6 |
1.5 2 |
1.1 1-1/2 |
.75 1 |
| 90L | 56 | 90 88.9 |
70 69.8 |
62.5 50.8 |
10 8.7 |
24 22.2 |
56 57.2 |
50 57.2 |
2.2 3 |
1.5 2 |
1.1 1-1/2 |
| 100L | 145T | 100 88.9 |
80 69.8 |
70 63.5 |
12 8.7 |
28 22.2 |
63 57.2 |
60 57.2 |
3 4 |
2.2 3 |
1.5 2 |
| 112L | 182T | 112 114.3 |
95 95.2 |
57 57.2 |
12 10.7 |
28 28 |
70 70 |
60 69.9 |
3.7 5 |
2.2 3 |
1.5 2 |
| 112M | 184T | 112 114.3 |
95 95.2 |
70 68.2 |
12 10.7 |
28 28 |
70 70 |
60 69.9 |
3.7 5 |
4 5-4/5 |
2.2 - |
| 132S | 213T | 132 133.4 |
108 108 |
70 69.8 |
12 10.7 |
38 34.9 |
89 89 |
80 85.7 |
7.5 10 |
5.5 7-1/2 |
3 - |
| 132M | 215T | 132 133.4 |
108 108 |
89 88.8 |
12 10.7 |
38 34.9 |
89 89 |
80 85.7 |
- - |
7.5 10 |
5.5 7-1/2 |
| 160M* | 254T | 160 158.8 |
127 127 |
105 104.8 |
15 13.5 |
42 41.3 |
108 108 |
110 101.6 |
15 20 |
11 15 |
7.5 10 |
| 160L* | 256T | 160 158.8 |
127 127 |
127 127 |
15 13.5 |
42 41.3 |
108 108 |
110 101.5 |
18.5 25 |
15 20 |
11 15 |
| 180M* | 284T | 180 177.8 |
139.5 139.8 |
120.5 120.2 |
15 13.5 |
48 47.6 |
121 121 |
110 117.5 |
22 - |
18.5 25 |
- - |
| 180L* | 286T | 180 177.8 |
139.5 139.8 |
139.5 139.8 |
15 13.5 |
48 47.6 |
121 121 |
110 117.5 |
22 - |
18.5 25 |
- - |
| 200M* | 324T | 180 203.3 |
159 158.8 |
133.5 133.4 |
19 16.7 |
55 54 |
133 133 |
110 133.4 |
30 40 |
30 40 |
- - |
| 200L* | 326T | 200 203.2 |
159 158.8 |
152.5 152.4 |
19 16.7 |
55 54 |
133 133 |
110 133.4 |
37 50 |
37 50 |
22 30 |
| 225S* | 364T | 225 228,6 |
178 117.8 |
143 142.8 |
19 16.7 |
60 60.3 |
149 149 |
140 149,2 |
- - |
37 50/75 |
30 40 |
| 225M* | 365 | 225 228.6 |
178 177.8 |
155.5 155.6 |
19 16.7 |
60 60.3 |
149 149 |
140 149.2 |
45 60/75 |
45 60/75 |
37 50 |
| 250M* | 405T | 250 254 |
203 203.2 |
174.5 174.6 |
24 20.6 |
65 73 |
168 168 |
140 182.2 |
55 75/100 |
55 75/100 |
- - |
| 280S* | 444T | 280 279.4 |
228.5 228.6 |
184 184.2 |
24 20.6 |
75 85.7 |
190 190 |
140 215.9 |
- - |
- - |
45 60/100 |
| 280M* | 445T | 280 279.4 |
228.5 228,6 |
209.5 209.6 |
24 20.6 |
75 85.7 |
190 190 |
140 215.9 |
- - |
- - |
55 75/125 |
+ Shaft dimensions of these IEC frames may vary between manufacturers.
Horsepower listed is closest comparable rating with similar mounting dimensions. In some instances, this results in a greater HP rating than required.
For example, 37KW 4 pole converts to 50HP but nearest HP rating in the NEMA frame having comparable dimensions is 75HP. In these instances, the HP rating printed in black is the direct conversion, and HP printed in blue is the HP of the dimensionally desirable frame.
OBSERVE CAUTION if the drive train or driven load is likely to be damaged by the greater HP.
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NEMA FRAME ASSIGNMENTS - OPEN & TEFC
| NEMA Frame Program |
3600 RPM | 1800 RPM | 1200 RPM | 900 RPM | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| T Frames 1964 |
U Frames 1952 |
Original NEMA Frames |
T Frames 1964 |
U Frames 1952 |
Original NEMA Frames |
T Frames 1964 |
U Frames 1952 |
Original NEMA Frames |
T Frames 1964 |
U Frames 1952 |
Original NEMA Frames |
|
| HP | ||||||||||||
| 1 | − | − | − | 143T | 182 | 203 | 145T | 184 | 204 | 182T | 213 | 225 |
| 1 1/2 | 143T | 182 | 203 | 145T | 184 | 204 | 182T | 184 | 224 | 184T | 213 | 254 |
| 2 | 145T | 184 | 204 | 145T | 184 | 224 | 184T | 213 | 225 | 213T | 215 | 254 |
| 3 | 145T/182T | 184 | 224 | 182T | 213 | 225 | 213T | 215 | 254 | 215T | 254U | 284 |
| 5 | 182T/184T | 213 | 225 | 184T | 215 | 254 | 215T | 254U | 284 | 254T | 256U | 324 |
| 7 1/2 | 184T/213T | 215 | 254 | 213T | 254U | 284 | 254T | 256U | 324 | 256T | 284U | 326 |
| 10 | 213T/215T | 254U | 284 | 215T | 256U | 324 | 256T | 284 | 326 | 284T | 286U | 364 |
| 15 | 215T/254T | 256U | 324 | 254T | 284U | 326 | 284T | 324U | 364 | 286T | 326U | 365 |
| 20 | 254T/256T | 284U/286U | 326 | 256T | 286U | 364 | 286T | 326U | 365 | 324T | 364U | 404 |
| 25 | 256T/284TS | 286U/324U | 364S/365S | 284T | 324U | 364/365 | 324T | 364U | 404 | 326T | 365U | 405 |
| 30 | 284TS/286TS | 324S/326S | 364S/404S | 286T | 326U | 365/404 | 326T | 365U | 405 | 364T | 404U | 444 |
| 40 | 286TS/324TS | 326S/364US | 365S/405S | 324T | 364U | 404/405 | 364T | 404U | 444 | 365T | 405U | 445 |
| 50 | 324TS/326TS | 364US | 404S/444S | 326T | 365US | 405S/444S | 365T | 405U | 445 | 404T | 444U | 504U |
| 60 | 326TS/364TS | 365US/405US | 405S/445S | 364TS | 404US/405US | 444S/445S | 404T | 444U | 504U | 405T | 445U | 505 |
| 75 | 364TS/365TS | 404US/444US | 444S/504S | 365TS | 405US/444US | 445S/504S | 405T | 445U | 505 | 444T | − | − |
| 100 | 365TS/405TS | 405US/445US | 445S/505S | 404TS/405TS | 444US/445US | 504S/505S | 444T | − | − | 445T | − | − |
| 125 | 404TS/444TS | 444US | 504S | 405TS/444TS | 445US | 505S | 445T | − | − | − | − | − |
| 150 | 405TS/445TS | 445US | 505S | 444TS/445TS | − | − | − | − | − | − | − | − |
| 200 | 444TS | − | − | 445TS | − | − | − | − | − | − | − | − |
| 250 | 445TS | − | − | − | − | − | − | − | − | − | − | − |
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CALCULATING CONVERSIONS
- Equivalent HP can be calculated by multiplying the KW rating by 1.341.
- Multiply HP by .7457 to convert HP to KW.
- To convert from millimeters to inches, multiply by .03937
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FRACTION/DECIMAL/MILLIMETER CONVERSIONS
| Inch- Fraction |
Inch- Decimal |
Millimeter | Inch- Fraction |
Inch- Decimal |
Millimeter | Inch- Fraction |
Inch- Decimal |
Millimeter | Inch- Fraction |
Inch- Decimal |
Millimeter |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/64 | 0.015625 | 0.397 | 17/64 | 0.265615 | 6.747 | 33/64 | 0.515625 | 13.097 | 49/64 | 0.765725 | 19.447 |
| 1/32 | 0.03125 | 0.794 | 9/32 | 0.28125 | 7.144 | 17/32 | 0.53125 | 13.494 | 25/32 | 0.78125 | 19.844 |
| 3/64 | 0.046875 | 1.191 | 19/64 | 0.296875 | 7.541 | 35/64 | 0.546875 | 13.891 | 51/64 | 0.796875 | 20.241 |
| 1/16 | 0.0625 | 1.588 | 5/16 | 0.3125 | 7.938 | 9/16 | 0.5625 | 14.288 | 13/16 | 0.8125 | 20.638 |
| 5/64 | 0.078125 | 1.984 | 21/64 | 0.328125 | 8.334 | 37/64 | 0.578125 | 14.684 | 53/64 | 0.828125 | 21.034 |
| 3/32 | 0.09375 | 2.381 | 11/32 | 0.34375 | 8.731 | 19/32 | 0.59375 | 15.081 | 27/32 | 0.84375 | 21.431 |
| 7/64 | 0.109375 | 2.778 | 23/64 | 0.359375 | 9.128 | 39/64 | 0.609375 | 15.478 | 55/64 | 0.859375 | 21.828 |
| 1/8 | 0.125 | 3.175 | 3/8 | 0.375 | 9.525 | 5/8 | 0.625 | 15.875 | 7/8 | 0.875 | 22.225 |
| 9/64 | 0.140625 | 3.572 | 25/64 | 0.390625 | 9.921 | 41/64 | 0.640625 | 16.272 | 57/64 | 0.890625 | 22.622 |
| 5/32 | 0.15625 | 3.969 | 13/32 | 0.40625 | 10.319 | 21/32 | 0.65625 | 16.669 | 29/32 | 0.90625 | 23.019 |
| 11/64 | 0.171875 | 4.366 | 27/64 | 0.421875 | 10.716 | 43/64 | 0.671875 | 17.066 | 59/64 | 0.921875 | 23.416 |
| 3/16 | 0.1875 | 4.762 | 7/16 | 0.4375 | 11.112 | 11/16 | 0.6875 | 17.462 | 15/16 | 0.9375 | 23.812 |
| 13/64 | 0.203125 | 5.129 | 29/64 | 0.453125 | 11.509 | 45/64 | 0.703125 | 17.859 | 61/64 | 0.953125 | 24.209 |
| 7/32 | 0.21875 | 5.556 | 15/32 | 0.46875 | 11.906 | 23/32 | 0.71875 | 18.256 | 31/32 | 0.96875 | 24.606 |
| 15/64 | 0.234375 | 5.953 | 31/64 | 0.484375 | 12.303 | 47/64 | 0.734375 | 18.653 | 63/64 | 0.984375 | 25.003 |
| 1/4 | 0.25 | 6.350 | 1/2 | 0.50 | 12.700 | 3/4 | 0.75 | 19.050 | 1 | 1.00 | 25.400 |
| MM | Inch | MM | Inch |
|---|---|---|---|
| 1 | 0.039 | 14 | 0.5519 |
| 2 | 0.079 | 15 | 0.5906 |
| 3 | 0.1181 | 16 | 0.63 |
| 4 | 0.1575 | 17 | 0.6693 |
| 5 | 0.1969 | 18 | 0.7087 |
| 6 | 0.2362 | 19 | 0.748 |
| 7 | 0.2756 | 20 | 0.7874 |
| 8 | 0.315 | 21 | 0.8268 |
| 9 | 0.3543 | 22 | 0.8661 |
| 10 | 0.3937 | 23 | 0.9055 |
| 11 | 0.4331 | 24 | 0.9449 |
| 12 | 0.4724 | 25 | 0.9843 |
| 13 | 0.5119 |
Frequently Asked Questions About Motor Frame Sizes
Where can I find an electric motor near me?
Use our Where to Buy tool to find electric motors from Regal Rexnord brands near you.
Can I use these charts to replace a motor from another brand?
If a motor is built to NEMA rigid base of C-face mounted dimensional standards, then the dimensions will not change from one brand to another. So yes, you can replace motors from another brand if that motor is a NEMA C-face mounted motor. However, consider other factors like horsepower, voltage, and phase when deciding on a replacement motor. To help find a replacement motor, use our Replacement Product Cross Reference Guide.
What do the dimension codes (e.g., “D”, “BA”, “C”) mean?
These codes denote distance from one physical point on a motor to another. See the diagrams above for more information about the dimension codes.
How do I know which frame size I need?
Physical dimensions and mounting configurations define NEMA motors. When buying a motor, your selection should fit within the available space and should be able to be mounted securely. Base the choice of your frame size off of available space and mounting.
Where do I find other types of ratings like IP/NEMA enclosure types?
IP ratings and NEMA enclosure types establish standards for motor enclosures, not motor sizes. For information about IP ratings, review the IP Ratings Guide. About Electric Motors has information on motor enclosures.
Where can I find 3D models or CAD drawings of motors?
You can find 3D CAD files of Regal Rexnord electric motors on individual product pages within the Regal Rexnord Electric Motor Catalog.
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Electric Motor Resources
Distributor Locator
Need to know where you can buy a Regal Rexnord brand product? Use the distributor locator to find distributors, wholesalers, or service centers near you.Information provided is based on standard operating procedures. Please consult your engineering team before any installations or modifications.
Page last updated: December 8, 2025