Airtac BSAI Locking Clamp Cylinder BSAI125X350S
The AirTAC Airtac BSAI Locking Clamp Cylinder BSAI125X350S is a genuine double-acting ISO 15552 cylinder with a Ø125mm bore, 350mm 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
- Stroke350 mm
- Cylinder portG1/2
- TypeSingle rod (BSAI)
- Enclasp portG1/8
- Rod threadM27×2
About the Airtac BSAI Locking Clamp Cylinder BSAI125X350S
The AirTAC BSAI125X350-S is a double-acting ISO 15552 profile cylinder equipped with a spring-applied, air-released clamp-lock mechanism. It delivers 6136 N of push thrust at 0.5 MPa and utilizes a 32 mm carbon steel rod with an M27x2 thread. A defining feature is its ability to lock the piston at any position along its 350 mm stroke, providing a robust static holding force of 8600 N. This bidirectional enclasp grips the rod securely whether the rod was extending or retracting.
It is critical to distinguish this 8600 N static holding force from the cylinder's 6136 N dynamic thrust—the clamp is sized to hold a static load, not to generate propulsion. The lock engages only after the cylinder has come to a complete stop, meaning it cannot brake a moving rod. Additionally, the system requires a third G1/8 enclasp port to release the lock, and pressures on both sides of the piston must be balanced during unlocking to prevent the rod from jumping abruptly. This unit includes a magnet for CMSE reed and DMSE electronic sensors.
Airtac BSAI Locking Clamp Cylinder BSAI125X350S Technical Specifications
| Model | Airtac BSAI Locking Clamp Cylinder BSAI125X350S |
|---|---|
| Series | BSAI ISO 15552 clamp-lock cylinder |
| Bore size | Ø125 mm |
| Stroke | 350 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 BSAI125X350S Is Used
Vertical Axis Load Holding
Freezes heavy vertical loads at any point in the 350 mm travel, preventing crashes under power loss with 8600 N of holding force.
Machining Position Fixture
Secures a workpiece mid-stroke for machining or inspection, ensuring the load remains entirely immobile without relying on live air pressure.
Emergency Power-Loss Hold
The spring-applied clamp engages instantly when air drops, locking the 32 mm carbon steel rod bidirectionally to halt equipment safely.
Is the Airtac BSAI Locking Clamp Cylinder BSAI125X350S the Right Clamp-Lock?
Choose this 125 mm bore model when an application demands extreme holding power mid-stroke, stepping up from the 100 mm bore which offers 3927 N thrust and a 5500 N holding force. The BSAI125X350-S is preferred over a SAIL stroke-end lock cylinder when the load must be frozen at an intermediate point rather than solely at the extremes. If position holding is entirely unnecessary, a plain SAI cylinder provides equivalent thrust without the clamp complexity. Because the stroke is 350 mm, an external guide is recommended to support the rod and prevent side-load damage.
This single-rod configuration features a PT tapered port thread, a 1/2 inch cylinder port, and the dedicated G1/8 enclasp port. It accepts Basic, FA, FB, CA, CB, CR, LB, TC, TCM1, and TCM2 mounts. The -S magnet enables precise tracking with AirTAC CMSE and DMSE switches. For safety-critical applications, remember that the clamp locks only after the rod stops and requires an additional independent safety measure if human safety depends on the hold.
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 BSAI125X350S FAQ
The clamp-lock provides a static holding force of 8600 N. It can secure the rod bidirectionally at any position along the 350 mm stroke, but it only engages after the cylinder has stopped moving.
The lock is released via a third G1/8 enclasp port, but only when the air pressures on both sides of the piston are balanced. If pressures are unbalanced during unlocking, the rod can move abruptly, posing a hazard.
Related AirTAC Lock & Standard Cylinders
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