Airtac BSAI Locking Clamp Cylinder BSAI125X125
The AirTAC Airtac BSAI Locking Clamp Cylinder BSAI125X125 is a genuine double-acting ISO 15552 cylinder with a Ø125mm bore, 125mm 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
- Stroke125 mm
- Cylinder portG1/2
- TypeSingle rod (BSAI)
- Enclasp portG1/8
- Rod threadM27×2
About the Airtac BSAI Locking Clamp Cylinder BSAI125X125
The AirTAC BSAI125X125 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released clamp-lock mechanism. A defining feature of this series is its ability to lock the piston rod at ANY position along the 125 mm stroke, providing a robust static holding force of 8600 N. This bidirectional enclasp grips the 32 mm carbon steel rod securely whether the rod was extending or retracting, operating within a 0.15-0.7 MPa pressure range and delivering a push thrust of 6136 N at 0.5 MPa.
It is critical to distinguish between the cylinder thrust and the clamp holding force; the 8600 N holding capacity is a separate static rating from the 6136 N pneumatic thrust, meaning you must size the clamp force against the static load, not the cylinder's movement power. Furthermore, the variable air cushion only decelerates the piston near the stroke ends and does not contribute to holding the load. The clamp operates via a dedicated G1/8 enclasp port, requiring balanced air pressure on both sides of the piston to unlock safely and prevent abrupt rod movement.
Airtac BSAI Locking Clamp Cylinder BSAI125X125 Technical Specifications
| Model | Airtac BSAI Locking Clamp Cylinder BSAI125X125 |
|---|---|
| Series | BSAI ISO 15552 clamp-lock cylinder |
| Bore size | Ø125 mm |
| Stroke | 125 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 BSAI125X125 Is Used
Vertical Load Holding
Maintains heavy vertical loads at any intermediate height along the 125 mm stroke using the 8600 N static holding force, preventing gravity-driven drops.
Power Loss Safety
The spring-applied clamp engages automatically upon air pressure loss or emergency stop, securely gripping the rod wherever it currently sits in the travel.
Machining Position Hold
Locks the workpiece rigidly in place during drilling or milling operations at a specific stroke position, isolating the load from pneumatic pressure fluctuations.
Is the Airtac BSAI Locking Clamp Cylinder BSAI125X125 the Right Clamp-Lock?
Choose the BSAI125X125 when an application requires mid-stroke holding that a plain SAI cylinder cannot provide, or when you need to hold a load anywhere in the travel rather than just at the stroke end like the SAIL series. If the 6136 N thrust at 0.5 MPa or the 8600 N holding force is insufficient, stepping up is not an option as 125 mm is the largest available bore in this range; conversely, if the load is lighter, an 80 mm bore offers 2513 N thrust and 3600 N holding force. The clamp locks only after the cylinder has stopped moving and cannot brake a moving rod, so human-safety-critical applications require an additional independent safety measure.
This single-rod configuration uses a PT ported design with a 1/2 cylinder port and a G1/8 enclasp port. It supports Basic, FA, FB, CA, CB, CR, LB, TC, TCM1, and TCM2 mountings. The substantial M27x2 rod thread and 32 mm rod diameter handle high side loads effectively. Since this model is supplied without a magnet (-S not specified), it cannot use CMSE or DMSE sensors for position feedback.
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 BSAI125X125 FAQ
The BSAI125X125 provides a static holding force of 8600 N. Unlike stroke-end locks, this clamp-lock mechanism can secure the load at ANY position along the 125 mm stroke. The holding force is bidirectional, gripping the rod securely whether the rod was extending or retracting.
The clamp is spring-applied and air-released via a dedicated G1/8 enclasp port. It only locks after the cylinder has stopped moving and cannot brake a moving rod. To unlock safely, the air pressures on both sides of the piston must be balanced; otherwise, the rod can move abruptly upon release.
Related AirTAC Lock & Standard Cylinders
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