STM SpA supplier in Romania
Industrial gearboxes, gear motors and mechanical variators
Founded in 1976 · Headquarters: Lippo di Calderara di Reno (Bologna), Italy
Who is STM SpA and what does it make?
STM SpA is an Italian manufacturer of gearboxes, gear motors and mechanical variable speed drives, based at Lippo di Calderara di Reno, near Bologna, founded in 1976. The range covers coaxial, parallel, shaft-mounted, right-angle and planetary gearboxes, worm gearboxes with worm wheel and worm screw, mechanical speed variators, electric motors and inverters, all designed as components for motion transmission in industrial machinery. From the STM portfolio we can quote either the gearbox on its own or the complete gear motor assembly, depending on what the customer needs on the production line.
STM positions itself in the segment of general-purpose industrial gearboxes, relying on a wide selection of construction types starting from the same manufacturing platform. The worm gearbox line includes the variants R (round body), U (square body), RR (combined, two stages) and CR (with gear pre-stage), to which are added the Z/ZL series angular gearboxes and the WMF series mechanical variators for continuous speed adjustment. The company reports a turnover of 152 million euros in 2023 and sales in 88 countries through 21 subsidiaries.
For installations in Romania, STM means access to general-purpose gearboxes for the conveyor belt, the industrial mixer or the packaging line, where a dedicated high-power gearbox is not needed, but rather a standardised range with many construction variants available from the factory.
What do we supply from the STM SpA range?
| Product | Description |
|---|---|
| R/U series worm gearboxes | Gearboxes with worm wheel and worm screw, available with round body (R series) or square body (U series), for applications that call for a high reduction ratio in a compact size. Typically mounted at the end of a standard electric motor, on conveyor belts, agitators or low-speed lifting mechanisms. For a quotation, the customer must send the input and output speed wanted, the torque needed at the output shaft and the mounting position. |
| RR/CR series combined gearboxes | Worm gearboxes in two stages (RR) or with a cylindrical gear pre-stage (CR), for reduction ratios higher than a single worm stage allows, keeping a reasonable size compared with an equivalent helical gearbox. They are used on machines where the motor has a high speed, but the driven mechanism needs a very low speed and high torque. The customer must specify the total reduction ratio required and the power of the driving motor. |
| WMF series mechanical variators | Mechanical speed variators that allow continuous adjustment of the output speed without an electronic inverter. They are useful on lines where the speed has to be adjusted frequently by the operator, but installing a frequency inverter is not economically or technically justified. For a quotation, the customer must send the speed range needed at the output and the driving power. |
| Gear motors and electric motors | Motor-gearbox assemblies pre-assembled at the factory, combining STM electric motors with any of the gearboxes in the range, plus inverters for variable speed control. They reduce design time for the customer, who receives a single sized assembly, not separate components to couple. The customer must send the power required, the output speed wanted and the supply voltage available. |
Why STM SpA?
- Very wide range of construction types — coaxial, parallel, shaft-mounted, right-angle, planetary and worm — in the same range
- Worm gearboxes in R, U, RR and CR variants, with gear pre-stage for high reduction ratios
- WMF series mechanical variators for continuous speed adjustment, without additional electronics
- Sales network declared in 88 countries
Which STM SpA codes and series are requested most often?
| Code | Description |
|---|---|
| Seria R | Round worm gearbox, shown together with torque limiters |
| Seria U | Square worm gearbox, compact variant from the standard range |
| Seria RR | Combined worm gearbox, with additional reduction stage |
| Seria CR | Worm gearbox with gear-type pre-stage |
| CAM pre-coupling | Pre-stage available for R and U series gearboxes |
| CBN pre-coupling | Alternative pre-stage variant for R and U series |
| Seria W | Square worm gearbox from the STM import range |
| Seria WMF | Mechanical speed variator for continuous speed adjustment |
| Seria Z | Angular gearbox for changing the direction of the output shaft |
| Seria ZL | Angular gearbox in a lighter, more compact variant |
| High Tech coaxial gearboxes | Coaxial gearboxes from the High Tech range for precision applications |
| Electronic geared motors | Electric motors and electronic variators from the STM Electronic range |
Where is STM SpA equipment used?
- Chemical industry — transmissions for mixers and dosing pumps
- Industrial conveyors — gear motors for belts and roller conveyors
- Lifting and handling — gearboxes for travel and lifting mechanisms
- Packaging and processing — mechanical variators for adjusting line speed
- Machine building — standardised gearboxes integrated into OEM equipment
How do we supply STM SpA in Romania?
For STM we work with the manufacturer's technical documentation — we have no stock of our own on this range and we say openly what we confirm after a case-by-case check of the code requested. Gearboxes and gear motors are brought in to order through EU supply channels, usually in 1–4 weeks from confirmation. For a correct quotation, the customer must send us the construction type wanted (R, U, RR, CR or other), the reduction ratio, the motor power and the mounting position on the machine. We do not promise permanent availability from stock and we do not confirm the availability of a specific code without first checking it at the source.
We check the availability of a specific STM gearbox case by case at the source; reconditioning of STM units in service is carried out outside our supply.
Frequently asked questions about STM SpA
What is the difference between STM SpA R series and U series gearboxes?
The R series has a round construction and is used together with torque limiters. The U series has a square construction, with a different housing shape, which may influence the way it is fixed to the structure of the driven equipment. The choice between the two depends mainly on the mounting configuration available and the accessories wanted.
Do you supply STM SpA gearboxes in Romania?
Yes, we bring in to order worm gearboxes of the R, U, RR or CR series, as well as Z and ZL angular gearboxes, on the basis of the manufacturer's full catalogue code. STM SpA gearboxes are brought in only to order, without prior storage on our side, and the lead time is usually 1–4 weeks from confirmation. We recommend stating the reduction ratio and the mounting position wanted.
What data are needed for a quotation on an STM SpA gearbox?
The reduction ratio wanted, the output torque required by the application and the mounting position, horizontal or vertical, of the gearbox are needed. It also matters whether a pre-stage, such as CAM or CBN, is needed for connection to a standard electric motor already present in the installation. These data allow the right choice between the R, U, RR and CR series, depending on the load transmitted.
What is the WMF series mechanical variator from STM SpA?
The WMF mechanical variator allows continuous adjustment of the output speed, without fixed steps, using an internal mechanical mechanism in place of an electronic frequency inverter. It is useful where the speed of a conveyor or a line has to be adjusted frequently, directly from a local button or lever. It is part of the standard STM range, alongside the worm and angular gearboxes.
How do I request a STM SpA quotation?
Send the STM SpA code from the nameplate and the quantity; we reply in English with availability and the lead time written in the quotation.
Request a quoteUpdated: 12 November 2026 · Sources: STM SpA (manufacturer documentation)