The FESTO DSM-6-180-P-A-FW, part number 185931, is a compact pneumatic semi-rotary drive designed for precise angular movement in automated machinery and light-duty handling systems. Built with a vane-type rotary design and double-acting operating principle, this model is engineered to deliver stable rotary motion within a 0° to 180° swivel angle, making it suitable for clamping, sorting, positioning, turning, and indexing functions in space-limited equipment. According to Festo product data, it features size 6, elastic cushioning at both ends, position detection via proximity switch, and a product weight of 56 g, which supports lightweight mechanical design and efficient integration into compact assemblies.
Technical Specifications
| Item | Specification |
|---|---|
| Brand | FESTO |
| Part Number | 185931 |
| Model | DSM-6-180-P-A-FW |
| Product Type | Semi-rotary drive |
| Operating Principle | Double-acting |
| Design | Vane |
| Size | 6 |
| Swivel Angle | 0° to 180° |
| Cushioning | Elastic cushioning rings/plates at both ends |
| Cushioning Angle | 0.5° |
| Position Detection | Via proximity switch |
| Operating Pressure | 0.35 MPa to 0.8 MPa / 3.5 bar to 8 bar |
| Max. Swivel Frequency at 6 bar | 3 Hz |
| Repetition Accuracy | 1° |
| Theoretical Torque at 6 bar | 0.15 Nm |
| Permissible Mass Moment of Inertia | 6.5E-4 kgm² |
| Pneumatic Connection | M3 |
| Mounting Type | Via female thread |
| Ambient Temperature | 0 °C to 60 °C |
| Product Weight | 56 g |
| Housing Material | Anodised |
| Drive Shaft Material | High-alloy stainless steel |
| Seal Material | TPE-U (PU) |
| Compliance Notes | RoHS-compliant; cleanroom class 6 according to ISO 14644-1; compressed air to ISO 8573-1:2010 [7:4:4] |
Source for the specification table: Festo official product page and DSM datasheet for part number 185931.
Product Description
The FESTO DSM-6-180-P-A-FW is intended for applications where a controlled rotary motion must be achieved without the complexity of an electric servo axis. Its compact pneumatic structure allows machine designers to create efficient motion sequences while reducing installation space, wiring complexity, and overall system mass. Because the actuator uses compressed air and a vane-based internal design, it is particularly well suited for repetitive switching and positioning duties in packaging equipment, electronic assembly stations, laboratory automation, and small transfer mechanisms. The official Festo data indicates a maximum swivel frequency of 3 Hz at 6 bar, showing that this unit is optimized for reliable cyclic performance in compact automation tasks rather than for heavy-duty torque transmission.
One of the most practical advantages of this model is its 180-degree rotary movement, which gives equipment builders enough angular travel for many standard machine motions such as part turning, flap actuation, diverter control, and orientation adjustment. In many industrial systems, a 90-degree actuator may be too limited, while a more complex electric rotary axis may be excessive in both cost and design effort. The DSM-6-180-P-A-FW fits neatly between those two extremes. It provides a simple and dependable motion solution for machines that need repeatable rotary travel over a wide angular range while still maintaining a compact footprint. The 1-degree repetition accuracy listed by Festo makes it suitable for applications where consistent end positioning is required for downstream process stability.
Another important feature is the actuator’s double-acting pneumatic operation, which enables powered movement in both rotational directions. This is significant in automation because it improves motion control compared with spring-return designs and supports balanced cycle behavior. In fast-moving equipment, symmetrical actuation can help maintain predictable timing and reduce variation in switching performance. Festo also equips this version with elastic cushioning rings or plates at both ends, which helps soften end-position impacts and can contribute to lower mechanical stress on connected tooling or fixtures. This kind of cushioning is valuable in compact machinery where excessive shock loads can shorten the service life of adjoining brackets, couplings, and sensor mounts.
From an installation standpoint, the DSM-6-180-P-A-FW is designed for straightforward integration. The unit uses female-thread mounting and an M3 pneumatic connection, making it suitable for small pneumatic circuits and compact fixture assemblies. The relatively low product weight of 56 g is especially useful when designers are trying to minimize moving mass or when the actuator is being mounted on lightweight frames, miniature indexing structures, or modular machine components. A lighter actuator can help reduce inertia in the overall mechanism and may simplify bracket design in applications where every gram matters. For compact automation modules, this is a meaningful advantage.
Material selection also supports industrial reliability. Festo specifies a high-alloy stainless steel drive shaft, TPE-U (PU) seals, and an anodised housing. These material choices suggest a design focused on durability, corrosion resistance in normal industrial environments, and dependable sealing performance during repeated pneumatic cycling. The published data also notes RoHS compliance, which is relevant for users who need to align component selection with modern material and environmental requirements. In addition, the actuator is listed with cleanroom class 6 according to ISO 14644-1 and LABS conformity, making it more attractive for controlled production environments or sensitive manufacturing areas where contamination behavior may be a consideration.
In practical machine design, torque and inertia limits are key selection factors. Festo states a theoretical torque of 0.15 Nm at 0.6 MPa (6 bar) and a permissible mass moment of inertia of 6.5E-4 kgm². These figures show that the DSM-6-180-P-A-FW is intended for light rotary tasks, precision movement of small parts, and compact tooling functions rather than large or high-inertia loads. For engineers, this means the actuator should be applied where the driven arm, fixture, or workpiece remains within the rated inertia envelope. When correctly matched, the unit can provide stable, repeatable motion with low space demand and low pneumatic complexity. When overloaded, however, cycle quality and service life may be affected, so proper selection remains essential.
The operating range of 3.5 to 8 bar and ambient temperature range of 0 °C to 60 °C make this actuator suitable for many standard factory pneumatic systems. Festo also specifies compressed air quality according to ISO 8573-1:2010 [7:4:4], and notes that lubricated operation is possible, but once lubrication is used it will continue to be required. This is a typical and important maintenance consideration for pneumatic equipment. In production environments, consistent air preparation and correct operating media management are critical for preserving seal life and maintaining repeatable actuator performance over time.
Overall, the FESTO 185931 DSM-6-180-P-A-FW is a strong choice for designers and buyers who need a compact, lightweight, and reliable pneumatic semi-rotary actuator for 180-degree movement. Its combination of small size, proximity-switch position detection, double-acting vane construction, low weight, and established Festo build quality makes it suitable for a broad range of automation tasks where simple rotary motion is more important than high torque output. For systems focused on compactness, clean integration, and dependable repetitive operation, this model represents a practical and well-balanced solution within the DSM family.
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FESTO 185931 DSM-6-180-P-A-FW is a compact semi-rotary drive with 180-degree swivel angle, 56 g weight, double-acting vane design, M3 connection, and reliable pneumatic positioning for industrial automation.
