The SMC CRB2BW20-180SZ is a compact vane-type pneumatic rotary actuator designed for controlled quarter-turn and half-turn indexing duties in industrial automation. This model belongs to SMC’s CRB2 series, a rotary actuator family built for applications that need reliable oscillating motion, compact installation, and simple pneumatic control. Official SMC series information identifies the CRB2 platform as a vane-type rotary actuator available in multiple bore sizes and rotation angles, with support for direct mounting, flexible port orientation, and angle adjustment configurations across the range.
For the specific model code CRB2BW20-180SZ, the part number structure indicates a size 20 body, double-shaft configuration, and 180° rotation angle. Distributor and catalog references for this exact part confirm that it is a single-vane, double-acting pneumatic rotary actuator with 180° angular travel, 20 mm bore size, M5 port thread, and rubber cushioning. Public technical listings also identify the shaft style as double shaft with single flat, which is useful for couplings, fixtures, linkages, and positioning components that need a stable mechanical interface on both sides of the actuator.
A key commercial detail for this model is the product weight. Multiple current distributor listings for the exact part number show the weight at 0.103 kg, or 103 g. An RS Online technical datasheet excerpt for CRB2BW20-180SZ states the weight as 0.103 Kg, and current RS product pages present the same value as 103 g. A separate industrial spare-parts listing also repeats 103 g, which strengthens confidence that this is the correct published unit weight for the standard model.
Key Specifications
| Item | Specification |
|---|---|
| Brand | SMC |
| Model | CRB2BW20-180SZ |
| Product Type | Pneumatic Rotary Actuator |
| Series | CRB2 |
| Operating Principle | Vane Type |
| Action Type | Double Acting |
| Vane Type | Single Vane |
| Bore Size | 20 mm |
| Rotation Angle | 180° |
| Shaft Style | Double Shaft with Single Flat |
| Port Thread Size | M5 x 0.8 |
| Cushioning | Rubber |
| Maximum Operating Pressure | 0.7 MPa |
| Minimum Operating Temperature | 5°C |
| Maximum Operating Temperature | 60°C |
| Approximate Net Weight | 103 g |
The table above is compiled from current exact-model distributor data and SMC series references.
Product Structure and Working Principle
The CRB2BW20-180SZ uses a vane-type rotary mechanism rather than a rack-and-pinion design. In a vane-type actuator, compressed air acts directly on a vane connected to the output shaft, generating rotary motion inside the body. RS’s technical series description explains that the vane slides along the inner surface of the body and rotates until it contacts the stopper, while air supplied to the opposite chamber drives motion in the reverse direction. This design is valued in factory automation because it keeps the structure compact, reduces the number of moving transmission elements, and provides clean oscillating motion for indexing, opening, turning, and positioning tasks.
Because this version is double acting, air pressure is used for both clockwise and counterclockwise motion. That matters in real production equipment. Double-acting rotary actuators generally offer more balanced motion control, better cycle consistency, and more predictable repeat performance than spring-return designs, especially in repetitive machinery where the actuator must rotate the same load through the same angle many times per shift. The CRB2 family is also designed for direct mounting and flexible installation, which helps machine builders reduce bracket complexity and simplify mechanical layout.
Functional Advantages
One of the biggest advantages of the SMC CRB2BW20-180SZ is its compact form factor relative to its function. Distributor dimensional references show this model at roughly 42 × 42 × 59 mm, making it suitable for machines where space is limited but controlled rotary motion is still required. In compact automation stations, designers often need to rotate a stopper, clamp arm, small jig, sensor bracket, or part transfer arm without installing a large rotary table. This is exactly the type of duty where a vane actuator like the CRB2BW20-180SZ fits well.
Another strength is the 180° oscillation angle. That travel range is common in industrial tasks that need a full half-turn or a clear open/close movement between two positions. Typical examples include turning a part presentation fixture, flipping a sensor bracket, rotating a small mechanical gate, or indexing an arm between loading and unloading positions. SMC’s official CRB2 series page lists 90°, 100°, 180°, and 270° angle options in the family, and the selected 180° version gives a broad but still highly practical swing range for many automation mechanisms.
The double-shaft arrangement is also commercially and mechanically useful. A double shaft can make fixture design easier because power transmission or positioning references can be taken from either side of the actuator. In some machines, one side drives the working member while the opposite side is used for sensing, stop positioning, or secondary linkage. The product listings for this exact model identify it as double shaft with single flat, which is a practical shaft format for repeatable coupling and anti-slip mounting.
Performance and Application Suitability
The published maximum operating pressure of 0.7 MPa places this actuator within the normal range for factory pneumatic systems. The listed temperature range of 5°C to 60°C also aligns with standard indoor industrial conditions. These parameters make the CRB2BW20-180SZ suitable for general automation environments such as assembly machines, packaging equipment, small handling systems, indexing devices, test fixtures, and production tooling that use clean compressed air.
From a design standpoint, the model is especially attractive when the engineer wants simple rotational indexing without overcomplicating the mechanism. An electric rotary stage may provide programmable motion, but it also adds cost, controls complexity, and wiring requirements. A vane-type pneumatic actuator like this one is often a better choice when the motion is fixed-angle, repetitive, and binary in nature. For example, if the machine only needs to rotate from position A to position B and back again, a pneumatic rotary actuator is often faster to integrate and easier to maintain. That is one reason vane actuators remain common in industrial machinery despite the growth of servo-based motion systems. This conclusion is an engineering inference based on the published form factor, operating method, and standard pneumatic duty profile of the CRB2 family.
Typical Industrial Uses
| Industry or System | Example Use of CRB2BW20-180SZ |
|---|---|
| Assembly Equipment | Turning small fixtures or workpiece holders |
| Packaging Machinery | Opening and closing diverters or compact rotary gates |
| Inspection Stations | Rotating sensor arms or camera brackets |
| Transfer Mechanisms | Indexing a part from one orientation to another |
| Pneumatic Tooling | Oscillating clamp arms or process levers |
| Test Benches | Repetitive two-position angular movement |
These use cases are consistent with the technical nature of a compact 180° vane-type actuator and the installation flexibility highlighted in SMC’s CRB2 series information.
Why Buyers Choose This Model
For industrial buyers, the SMC CRB2BW20-180SZ offers a practical combination of brand reliability, compact size, simple pneumatic control, and clear fixed-angle motion. The 103 g weight is low enough for compact machine assemblies and for mechanisms where reducing moving mass helps overall cycle performance. The 20 mm size gives it a useful balance between compactness and output capability, while the 180° motion covers a wide range of indexing and turning functions. The fact that this is a standard SMC model also improves sourcing confidence, replacement continuity, and cross-market availability through industrial distribution channels.
Conclusion
The SMC CRB2BW20-180SZ is a compact double-acting vane-type pneumatic rotary actuator engineered for dependable 180° oscillating motion in industrial automation. With its 20 mm body size, double-shaft output, M5 port connection, rubber cushioning, and published weight of 103 g, it is well suited for equipment that needs repeatable angular movement in a small installation envelope. For assembly lines, packaging equipment, test fixtures, and general factory machinery, it is a straightforward and effective choice when a fixed-angle pneumatic rotary solution is preferred over more complex electric motion hardware.
