The SMC CJ2B16-30Z is a compact round body pneumatic cylinder from SMC’s CJ2 series, built for automation tasks that need reliable linear motion in a small footprint. This model combines a 16 mm bore with a 30 mm stroke, making it a practical choice for short-travel pushing, positioning, light clamping, part stopping, and indexing actions on assembly and packaging equipment. In real production lines, cylinders in this size range often become the “silent workforce” behind gates, stoppers, diverters, and small slides—components that cycle all day without asking for attention, until you choose the wrong one.
What makes the CJ2 series appealing is the balance between compact size and industrial survivability. A miniature cylinder is not just “small”; it has to tolerate frequent cycling, imperfect air quality, and mounting constraints that are never as clean as the CAD model. The CJ2B16-30Z is typically supplied as a double-acting, single-rod cylinder with rubber bumper cushioning, which helps reduce end-of-stroke shock in many everyday applications. RS Online’s listing for CJ2B16-30Z shows double acting, single rod, and rubber bumper cushioning, which matches how this product is commonly specified and purchased.
Another practical advantage is the CJ2 family’s strong ecosystem: mounting styles, accessories, speed controllers, fittings, and auto switches are widely available. That ecosystem matters because most downtime isn’t caused by the cylinder itself—it’s caused by awkward integration, hard-to-source spares, or inconsistent replacements. A standard, widely used cylinder series reduces those risks.
From a design point of view, a 16 mm bore is often chosen when you want decent thrust while keeping air consumption controlled. The 30 mm stroke is long enough for a clear mechanical “move,” but short enough to keep cycle times quick and the assembly compact. The CJ2B16-30Z is therefore a sensible default for equipment builders and maintenance teams who need a compact cylinder that fits typical brackets and plates without turning the machine into a custom one-off.
Specification Table (CJ2B16-30Z)
| Item | Specification / Description |
|---|---|
| Manufacturer | SMC |
| Series | CJ2 (Miniature / Round Body Air Cylinder) |
| Model | CJ2B16-30Z |
| Bore Diameter | 16 mm |
| Stroke | 30 mm |
| Action Type | Double acting, single rod (typical for this model) |
| Cushioning | Rubber bumper (commonly specified for CJ2B16-30Z) |
| Typical Applications | Stoppers, small pushers, light clamps, gates, indexing, part transfer |
| Net Weight | 126 g (0.126 kg) |
| Gross Weight | 132 g |
| Sourcing Reference | Official SMC web catalog entry exists for CJ2B16-30Z |
Performance and Integration Notes (What Matters in the Real World)
1) Compact motion that stays controllable
Short-stroke cylinders can be deceptively fast. The CJ2B16-30Z is often used in high-cycle processes because it can extend and retract quickly, especially when paired with properly sized valves and tubing. For stable operation, most users tune speed using inline speed controllers (meter-out is common) and make sure the end-of-stroke impact is acceptable for the mechanism.
2) Rubber bumpers help with everyday abuse
Rubber bumpers do not turn a cylinder into a precision shock absorber, but they do reduce harsh metal-to-metal impact. This is useful in stations where the cylinder hits the end position thousands of times per shift.
3) Keep side-loads out of the rod
Miniature cylinders are happiest when the load is axial (straight push/pull). If your design forces side-load (for example, the rod pushes a part that binds in a track), you’ll get faster wear and inconsistent motion. If side-load is unavoidable, add a guide mechanism or redesign the contact geometry so the cylinder only supplies thrust, not guidance.
4) Air quality and lubrication habits matter
Even a tough cylinder can be slowly ruined by dirty air, water carryover, or incompatible lubricants. Use a filter-regulator appropriate for your plant standard, and keep the air dry enough for consistent seal life. This is boring advice—also the advice that prevents 80% of “mystery failures.”
Common Use Cases
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Stopper cylinders on conveyors: A 30 mm stroke often provides enough travel to stop a moving part cleanly while keeping the bracket compact.
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Short pushers in assembly: Push a component into a nest, present a part to a sensor, or eject a finished piece.
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Fixture assists: Light clamping or positioning where you need repeatable motion but not a large clamping force.
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Gates and diverters: Simple on/off movement to open/close a path in a feeder or chute.
Summary
The SMC CJ2B16-30Z is a practical miniature cylinder built for compact automation: 16 mm bore, 30 mm stroke, typically double acting, single rod, and commonly specified with rubber bumper cushioning.
