QUICK REFERENCE MOTOR DIMENSIONS
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® motors and may differ from other brands. 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.
The overall length (“C” dimension) will change with the enclosure, horsepower and speed for the same brand and will vary from one brand to another for motors of the same HP, speed or enclosure. For detailed dimensions of all LEESON motors, go to “products” then “product catalog” on www.leeson.com
* NEMA C face motors also having 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”
^ 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.
RIGID MOUNT


C-FACE


NEMA T FRAME 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 |
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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 |
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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 |
IEC/NEMA COMPARISON
DIMENSION IN MELLIMETERS | KW/HP~ FRAME AS- SIGNMENTS 3 Phase-TEFC |
|||||||||
ICE NEMA |
D | E | F | H | U | BA | N-W | 2 Pole | 4 Pole | 6 Pole |
56 | 56 | 45 | 35.5 | 5.8 | 9 | 36 | 20 | − | − | − |
NA | − | − | − | − | − | − | − | − | − | − |
63 | 63 | 50 | 40 | 7 | 11 | 40 | 23 | .25 KW | .18 KW | − |
42 | 66.7 | 44.5 | 21.4 | 7.1 | 9.5 | 52.4 | − | 1/3 HP | 1/4 HP | − |
71 | 71 | 56 | 45 | 7 | 14 | 45 | 30 | .55 | .37 | − |
48 | 76.2 | 54 | 34.9 | 8.7 | 12.7 | 63.5 | 38.1 | 3/4 | 1/2 | − |
80 | 80 | 62.5 | 50 | 10 | 19 | 50 | 40 | 1.1 | .75 | .55 KW |
56 | 88.9 | 61.9 | 38.1 | 8.7 | 15.9 | 69.9 | 47.6 | 1 1/2 | 1 | 3/5 HP |
90S | 90 | 70 | 50 | 10 | 24 | 56 | 50 | 1.5 | 1.1 | .75 |
143T | 88.9 | 69.8 | 50.8 | 8.7 | 22.2 | 57.2 | 57.2 | 2 | 1 1/2 | 1 |
90L | 90 | 70 | 62.5 | 10 | 24 | 50 | 54 | 2.2 | 1.5 | 1.1 |
145T | 88.9 | 69.8 | 63.5 | 8.7 | 22.2 | 57.2 | 57.2 | 3 | 2 | 1 1/2 |
100L | 100 | 80 | 70 | 12 | 28 | 63 | 60 | 3 | 2.2 | 1.5 |
NA | − | − | − | − | − | − | − | 4 | 3 | 2 |
112S | 112 | 95 | 57 | 12 | 28 | 70 | 60 | 3.7 | 2.2 | 1.5 |
182T | 114.3 | 95.5 | 57.2 | 10.7 | 28 | 70 | 69.9 | 5 | 3 | 2 |
112M | 112 | 95 | 70 | 12 | 28 | 70 | 60 | 3.7 | 4 | 2.2 |
184T | 114.3 | 95.2 | 68.2 | 10.7 | 28 | 70 | 69.9 | 5 | 5.4/5 | − |
132S | 132 | 108 | 70 | 12 | 38 | 89 | 80 | 7.5 | 5.5 | 3 |
213T | 133.4 | 108 | 69.8 | 10.7 | 34.9 | 89 | 85.7 | 10 | 7 1/2 | − |
132M | 132 | 108 | 89 | 12 | 38 | 89 | 80 | − | 7.5 | 5.5 |
215T | 134.4 | 108 | 88.8 | 10.7 | 34.9 | 89 | 85.7 | − | 10 | 7 1/2 |
160M+ | 160 | 127 | 105 | 15 | 42 | 108 | 110 | 15 | 11 | 7.5 |
254T | 158.8 | 127 | 104.8 | 13.5 | 41.3 | 108 | 101.6 | 20 | 15 | 10 |
160L+ | 160 | 127 | 127 | 15 | 42 | 108 | 110 | 18.5 | 15 | 11 |
256T | 158.8 | 127 | 127 | 13.5 | 41.3 | 108 | 101.6 | 25 | 20 | 15 |
180M+ | 180 | 139.5 | 120.5 | 15 | 48 | 121 | 110 | 22 | 18.5 | − |
286T | 177.8 | 139.8 | 120.2 | 13.5 | 47.6 | 121 | 117.5 | − | 25 | − |
180L+ | 180 | 139.5 | 139.5 | 15 | 48 | 121 | 110 | 22 | 22 | 15 |
286T | 177.8 | 139.8 | 139.8 | 13.5 | 47.6 | 121 | 117.5 | 30 | 30 | 20 |
200M+ | 180 | 159 | 133.5 | 19 | 55 | 133 | 110 | 30 | 30 | − |
324T | 230.3 | 158.8 | 133.4 | 16.7 | 54 | 133 | 133.4 | 40 | 40 | − |
200L+ | 200 | 159 | 152.5 | 19 | 55 | 133 | 110 | 37 | 37 | 22 |
326T | 203.2 | 158.8 | 152.4 | 16.7 | 54 | 133 | 133.4 | 50 | 50 | 30 |
225S+ | 225 | 178 | 143 | 19 | 60 | 149 | 140 | − | 37 | 30 |
364T | 228.6 | 117.8 | 142.8 | 16.7 | 60.3 | 149 | 149.2 | − | 50/75 | 40 |
225M+ | 225 | 178 | 155.5 | 19 | 60 | 149 | 140 | 45 | 45 | 37 |
365T | 228.6 | 177.8 | 155.6 | 16.7 | 60.3 | 149 | 149.2 | 60/75 | 60/75 | 50 |
250M+ | 250 | 203 | 174.5 | 24 | 65 | 168 | 140 | 55 | 55 | − |
405T | 254 | 203.2 | 174.6 | 20.6 | 73 | 168 | 184.2 | 75/100 | 75/100 | − |
280S+ | 280 | 228.5 | 184 | 24 | 75 | 190 | 140 | − | − | 45 |
444T | 279.4 | 228.6 | 184.2 | 20.6 | 85.7 | 190 | 215.9 | − | − | 60/100 |
280M+ | 280 | 228.5 | 209.5 | 24 | 75 | 190 | 140 | − | − | 55 |
445T | 279.4 | 228.6 | 209.6 | 20.6 | 85.7 | 190 | 215.9 | − | − | 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 int he 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.
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
To convert from inches to millimeters, multiply by 25.4
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 | − | − | − | − | − | − | − | − | − | − | − |
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 |