Airtac BSAI Locking Clamp Cylinder BSAI125X300
The AirTAC Airtac BSAI Locking Clamp Cylinder BSAI125X300 is a genuine double-acting ISO 15552 cylinder with a Ø125mm bore, 300mm stroke and a spring-applied, air-released clamp-lock that holds the rod at ANY position along its travel — with a static holding force of 8600 N.
- BoreØ125 mm
- Stroke300 mm
- Cylinder portG1/2
- TypeSingle rod (BSAI)
- Enclasp portG1/8
- Rod threadM27×2
About the Airtac BSAI Locking Clamp Cylinder BSAI125X300
The AirTAC BSAI125X300 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released clamp-lock mechanism. It provides a robust static holding force of 8600 N, gripping the 32 mm carbon steel rod securely at any position along its 300 mm stroke. Delivering 6136 N of thrust at 0.5 MPa, this pneumatic actuator is designed for heavy-duty operations requiring reliable load retention without maintaining live air pressure.
A critical distinction exists between the cylinder thrust and the clamp holding force: the 8600 N holding capacity is a separate static metric used to size against gravity, not the 6136 N push force. Furthermore, the variable air cushions only decelerate the piston near stroke ends; the mechanical clamp is the sole device holding the load. Unlocking requires a third G1/8 enclasp port and balanced cylinder pressures to prevent the rod from jumping abruptly upon release.
Airtac BSAI Locking Clamp Cylinder BSAI125X300 Technical Specifications
| Model | Airtac BSAI Locking Clamp Cylinder BSAI125X300 |
|---|---|
| Series | BSAI ISO 15552 clamp-lock cylinder |
| Bore size | Ø125 mm |
| Stroke | 300 mm |
| Type | Single rod (BSAI), double acting |
| Cylinder port | G1/2 |
| Rod thread | M27×2 |
| Lock type | Spring-applied, air-released clamp (any position) |
|---|---|
| Static holding force | 8600 N |
| Enclasp / unlock port | G1/8 |
| Operating pressure | 0.15 – 0.7 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 500 mm/s |
| Max stroke | Up to 1000 mm |
Specifications follow the official AirTAC BSAI datasheet (ISO 15552). Operating pressure is 0.15–0.7 MPa (lower than a plain SAI). Port options: PT / G.
How the Clamp-Lock Holds
static holding force (Ø125 mm)
A spring-applied gripper clamps the rod and holds the load at any position in the stroke — not just at the stroke end (that is a SAIL) — and it is bidirectional: it holds whether the rod was extending or retracting.
Theoretical Output Force (Ø125mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 6136 N | 5734 N |
| 0.7 MPa (max) | 8590 N | — |
Push/pull as tabulated. Rated to the 0.7 MPa operating maximum for this series. The clamp holding force (8600 N) is separate from cylinder thrust. Size with a margin.
Where the Airtac BSAI Locking Clamp Cylinder BSAI125X300 Is Used
Machining Position Hold
Secures heavy workpieces at any point in the stroke for machining or inspection, maintaining a rigid 8600 N grip without requiring continuous air supply.
Vertical Axis Safety
Prevents heavy vertical loads from dropping when air pressure is lost, locking the 32 mm rod instantly once the cylinder stops moving.
Emergency Power Loss Hold
Acts as a fail-safe gripper during unexpected power outages, freezing the actuator in its current position rather than relying on end-of-stroke cushions.
Is the Airtac BSAI Locking Clamp Cylinder BSAI125X300 the Right Clamp-Lock?
Choose this 125 mm bore when an application demands substantial holding capacity that a smaller bore cannot provide; for context, stepping down to an 80 mm bore reduces the holding force to 3600 N and the 0.5 MPa thrust to 2513 N. Select the BSAI clamp-lock over a SAIL model when you need to secure the load at any intermediate stroke position, rather than only at the stroke end. If position holding is entirely unnecessary, a plain SAI cylinder suffices.
When replacing or specifying this unit, confirm the single-rod configuration, 300 mm stroke, PT tapered port threads, and the 1/2 inch cylinder ports. The correct mounting set includes Basic, FA, FB, CA, CB, CR, LB, TC, TCM1, and TCM2. Because this model lacks the -S magnet, it cannot host CMSE or DMSE sensors. Since the stroke is 300 mm, an external guide is recommended to manage side loads on the extended rod. Remember the clamp locks only after the rod stops moving; it cannot brake a moving load, and safety-critical applications require an independent external safety measure.
Quick checklist
- ✓ Hold needed at any position?
- ✓ Or stroke-end only → use SAIL
- ✓ Holding force ≥ your load
- ✓ Balanced-pressure unlock circuit
- ✓ Extra safety measure for people
Airtac BSAI Locking Clamp Cylinder BSAI125X300 FAQ
The BSAI125X300 features a static holding force of 8600 N. The spring-applied clamp grips the rod at any position along the 300 mm stroke, securely holding the load without live air pressure.
The clamp locks only after the cylinder has stopped moving; it cannot brake a moving rod. To unlock it safely via the G1/8 enclasp port, the air pressures on both sides of the piston must be balanced, otherwise the rod may move abruptly. Human safety applications require an additional independent safety measure.
Related AirTAC Lock & Standard Cylinders
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