NEMA / IEC frame cross-reference
The two standards were drawn up independently, so equivalence is by power and mounting — never by dimension. The table below pairs the frames and puts both shaft diameters side by side, because that is the number that decides whether a swap needs a new coupling.
| NEMA frame | NEMA shaft | IEC frame | IEC shaft | Mounting | LEADGO model |
|---|---|---|---|---|---|
| 143T | 7/8″ · 22.2 mm | 90L | 24 mm | B3 / B5 | YE3-90L |
| 145T | 7/8″ · 22.2 mm | 100L | 28 mm | B3 / B5 | YE3-100L |
| 184T | 1-1/8″ · 28.6 mm | 132M | 38 mm | B3 / B5 | YE3-132M |
| 215T | 1-3/8″ · 34.9 mm | 160M | 42 mm | B3 / B5 | YE3-160M |
| 256T | 1-5/8″ · 41.3 mm | 200L | 55 mm | B3 / B5 | YE3-200L |
| 326T | 2-1/8″ · 54.0 mm | 250M | 65 mm | B3 / B5 | YE3-250M |
| 365T | 2-3/8″ · 60.3 mm | 280S | 75 mm | B3 / B5 | YE3-280S |
| 405T | 2-7/8″ · 73.0 mm | 315S | 80 mm | B3 / B5 | YE3-315S |
Frame equivalence is by power and mounting, not by dimension — the two standards were drawn up independently and no NEMA frame is dimensionally identical to an IEC one. As the shaft columns show, a swap almost always needs a new coupling or a shaft adaptor, and the shaft extension length differs too. Check the dimension drawing for the specific model before ordering; the datasheets on the support page carry the full mounting dimensions.
Reading the table
A row says the two frames carry the same power at the same mounting, and nothing more. The foot bolt pattern, the flange, the shaft extension length and the shaft diameter all differ, and a T-frame motor coming out of a US plant will not drop onto the same base plate as its IEC counterpart without either new holes or an adaptor plate.
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