The SMC CQ2B25-5D is a compact pneumatic cylinder from SMC’s CQ2 family, built for machines where installation space is limited but consistent linear motion is still non-negotiable. In practice, this model is frequently selected for clamping, indexing, light pressing, stop mechanisms, and short-stroke pick-and-place tooling, especially when designers want a clean, low-profile actuator that is easy to mount and easy to service.
What makes the CQ2 line so widely used is the way it balances “small body” with “industrial reality.” Compact cylinders often get pushed into tight corners of an assembly station, then expected to run for a long time with minimal attention. The CQ2B25-5D is designed around that expectation: a standardized compact geometry (aligned with ISO 21287 listings) and a configuration that keeps plumbing and mounting straightforward.
Understanding the model code (practical decoding)
CQ2 indicates the compact cylinder series.
B indicates the through-hole mounting style commonly used for easy face mounting.
25 indicates a 25 mm bore size.
5 indicates a 5 mm stroke, which is the ultra-short travel version typically used for positioning, short clamping moves, or quick push/pull actions.
D is used in SMC CQ2 naming to identify a double-acting configuration in listings and datasheets for this part family.
The result is a compact actuator that can deliver useful force without taking up the space of a longer-stroke cylinder or a guided slide.
Key Specifications (CQ2B25-5D)
| Item | Specification |
|---|---|
| Manufacturer / Series | SMC, CQ2 Series Compact Cylinder |
| Model | CQ2B25-5D |
| Bore / Stroke | 25 mm bore / 5 mm stroke |
| Acting type | Double acting |
| Pressure medium | Compressed air |
| Operating pressure range | 0.05 to 1.0 MPa |
| Proof pressure | 1.5 MPa |
| Max piston speed | 500 mm/s |
| Temperature range | -10°C to +70°C |
| Port size (for Ø12–Ø25) | M5 x 0.8 |
| Pneumatic connections | 2 ports |
| Standards/approvals (listing) | ISO 21287 |
| Product weight | 0.086 kg (86 g) |
Weight note for logistics: The 2024 SMC/RS datasheet lists 0.086 kg. Some distributor pages show weights in pounds (for example 0.21221 lb, which is close to ~96 g). Differences usually come from rounding, packing conventions, or site-side unit conversion rather than a different cylinder.
Performance and engineering value in real applications
1) Compact force where you actually need it
A 25 mm bore cylinder provides a strong “force per footprint” ratio for many assembly tasks. Because this unit uses a 5 mm stroke, it is commonly deployed where the goal is not long travel, but repeatable engagement—for example, nudging a part into a locating feature, clamping a small fixture, or actuating a latch. Short strokes also tend to support fast cycle times when the air circuit is tuned correctly.
2) Predictable operation under industrial pressure conditions
The listed maximum operating pressure of 1.0 MPa and proof pressure of 1.5 MPa are typical values for robust pneumatic components, and they matter when the cylinder sits at the end of a manifold feeding multiple actuators. The specified operating pressure minimum (0.05 MPa) helps clarify that the cylinder is intended for normal pneumatic systems rather than ultra-low pressure specialty use.
3) Speed capability for modern automation
With a stated maximum piston speed of 500 mm/s, the CQ2B25-5D supports high-throughput station designs, especially for short motions where the cylinder spends more time “working” than “traveling.” In practice, real achievable speed depends on valve flow, tubing length, and load, but the rating is a useful indicator that the design is meant for brisk, repetitive movement.
4) Mounting and plumbing that reduce design pain
The B (through-hole) mounting style is popular because it makes mechanical integration clean: you can mount the cylinder body with accessible fasteners while keeping the actuator profile tight. For the Ø25 size class, the CQ2 catalog shows M5 x 0.8 ports, which is consistent with compact manifold layouts and tight tubing routing. This is the kind of detail that quietly saves time when you are packing multiple actuators into a dense tooling plate.
Typical use cases
| Application | Why CQ2B25-5D fits |
|---|---|
| Short clamping motion | 5 mm stroke is ideal for clamp-open/close actions without wasted travel |
| Part stop / gate in a feeder | Compact body and quick motion suit repeated stopping or releasing actions |
| Fixture locating assist | Short push with consistent bore force helps seat parts in nests |
| Small press or marking trigger | Short, controlled stroke supports simple pressing or triggering operations |
| Automated latch / lock actuation | Compact format and standardized pneumatic interface simplify integration |
Selection and integration tips (the stuff that prevents headaches)
Confirm stroke is truly enough: A 5 mm stroke is purposefully short. It is perfect for clamp jaws, gates, and stops, but it is not forgiving if tolerances stack up. Add a margin in your fixture design so the cylinder is not forced to “make up” for misalignment.
Tune speed with flow controls: The cylinder is rated for high speed, but fast movement without control can cause impact wear, noise, and inconsistent end positioning. Use speed controllers near the cylinder if possible and keep tubing runs short.
Plan around port and fitting size: Since the catalog lists M5 x 0.8 for this bore class, choose fittings and tubing that your maintenance team can standardize and stock.
Use weight for packaging accuracy: If you are building an export quote or calculating shipping mass, use 0.086 kg as the product reference weight from the datasheet.
Summary
The SMC CQ2B25-5D is a compact, standardized pneumatic cylinder optimized for short-stroke, high-cycle motion in tight automation environments. With a 25 mm bore, 5 mm stroke, double-acting operation, M5 porting for the Ø25 class, and a published net weight of 0.086 kg, it is a practical, production-friendly actuator for fixtures, clamps, stops, and fast positioning tasks—especially where designers want a reliable cylinder that does not consume precious machine volume.
