Bonfiglioli Bonfiglioli 300M
Bonfiglioli 300M series modular planetary gear units, in 20 sizes, with reference torques from 1,250 to 1,286,700 Nm.
The 300M is Bonfiglioli's series of modular planetary gear units for heavy-duty drives. The series has 20 sizes: 300, 301, 303, 304, 305, 306, 307, 309, 310M, 311M, 313M, 314M, 315M, 316M, 317M, 318M, 319, 321, 323 and 325, in coaxial or right-angle versions, foot or flange mounted. For the coaxial version, the catalogue gives reference torques of up to 1,286,700 Nm, transmission ratios of 3.4–2,916 and motors of 0.25–55 kW; the housing is made of spheroidal graphite cast iron. The gear units can be coupled with Bonfiglioli BN, BE, BX (IEC) asynchronous motors and, up to size 307, with the compact M, ME, MX motors.
The type code follows the structure in the catalogue: in 311M L2 16.7 HZ, "311M" is the size, "L" the coaxial version (R means right angle), "2" the number of reduction stages, "16.7" the transmission ratio and "HZ" the male splined output shaft for heavy loads. For a quotation, please send us the full code from the gear unit nameplate, the mounting position and the motor data; on order, the lead time is normally 1–4 weeks and, depending on the configuration, may be longer.
Models and codes
| Code | Note |
|---|---|
| 300 L | First size in the series; reference torque 1,250 Nm. |
| 301 L | Reference torque 2,460 Nm. |
| 303 L | Reference torque 2,970 Nm. |
| 307 L | Reference torque 15,680 Nm. |
| 310M L | Reference torque 33,640 Nm. |
| 316M L | Reference torque 134,390 Nm. |
| 321 L | Reference torque 655,740 Nm. |
| 325 L | Last size in the series; reference torque 1,286,700 Nm. |
Key specifications
| Sizes | 20 (from 300 to 325) |
|---|---|
| Reference torque M2REF (coaxial version) | 1.250 – 1.286.700 Nm |
| Transmission ratios (coaxial version) | 3.4 – 2.916 |
| Motor power (coaxial version) | 0.25 – 55 kW |
| Versions and mounting | coaxial (L) or right-angle (R); foot- or flange-mounted |
| Outputs | splined shaft (solid, heavy-duty, hollow), solid keyed shaft, hollow shaft with double keyway or for shrink disc |
| Brake | negative multi-disc brake, in configurations with hydraulic motor adapter |
| ATEX version | 2G/2D |
Manufacturer documentation for the 300M series, including the 300M IE2-IE3 catalogue (revision R4_1), is current, with no announcement of withdrawal from production.
Frequently asked questions
How do you read the code of a 300M gear unit?
The code begins with the size (for example 301 or 311M), followed by the version (L coaxial, R right angle), the number of reduction stages, the transmission ratio and the output type (for example HZ, splined shaft for heavy loads). The input follows (for example a flange for an IEC motor) and the options, such as the PV fluoroelastomer seal.
Can you quote the gear unit without a motor?
Yes. The catalogue provides a solid shaft input or a coupling flange for an IEC motor, from P71 to P250; please tell us which motor is in place, so that we can confirm the suitable flange.
What does the reference torque in the table mean?
It is the characteristic value of the size: the maximum rated torque Mn2 for a duration factor n2 × h = 10,000, in the single-stage configuration. In selection, what matters is the rated torque Mn2 at the chosen ratio, which must be at least equal to the torque required by the application.
Other Bonfiglioli series
We do not carry out the selection calculation (service factor, radial loads, cooling) for your application; we confirm the code and configuration from the Bonfiglioli catalogue. The values in the code table are reference torques per size, not rated torques for each ratio.
Updated: 2026-11-12