Airtac BSAI Locking Clamp Cylinder BSAI125X75S
The AirTAC Airtac BSAI Locking Clamp Cylinder BSAI125X75S is a genuine double-acting ISO 15552 cylinder with a Ø125mm bore, 75mm 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
- Stroke75 mm
- Cylinder portG1/2
- TypeSingle rod (BSAI)
- Enclasp portG1/8
- Rod threadM27×2
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac BSAI Locking Clamp Cylinder BSAI125X75S
The AirTAC BSAI125X75-S is a double-acting ISO 15552 profile cylinder equipped with a built-in clamp-lock mechanism. It uses a spring-applied, air-released gripper to secure the carbon steel piston rod at ANY position along its 75 mm travel, delivering a massive static holding force of 8600 N. Because this is a single-rod design, the forward thrust reaches 6136 N at 0.5 MPa (8590 N at the 0.7 MPa maximum). Remember that the 8600 N clamp holding force is a distinct quantity from the cylinder's thrust; you must size the holding capacity against your static load, not the pneumatic push force.
This unit includes a -S magnet for precise position sensing with AirTAC CMSE (reed) or DMSE (electronic) switches. The enclasp mechanism relies on a third G1/8 unlock port, separate from the 1/2 inch PT cylinder ports, and requires a balanced 0.15-0.7 MPa air pressure to release safely. Furthermore, the variable air cushions at the stroke ends only decelerate the piston; they do not hold the load. The clamp itself is bidirectional, locking the rod securely whether it was extending or retracting.
Airtac BSAI Locking Clamp Cylinder BSAI125X75S Technical Specifications
| Model | Airtac BSAI Locking Clamp Cylinder BSAI125X75S |
|---|---|
| Series | BSAI ISO 15552 clamp-lock cylinder |
| Bore size | Ø125 mm |
| Stroke | 75 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 BSAI125X75S Is Used
Machining Position Hold
Freezes a heavy workpiece at an exact intermediate stroke position to withstand machining forces without relying on live air pressure.
Vertical Load Arrest
Secures a massive vertical payload at any point in the travel, engaging its 8600 N holding force the moment the cylinder stops.
Power Loss Safety
The spring-applied clamp engages automatically during an air or power failure, holding the load exactly where it halted.
Is the Airtac BSAI Locking Clamp Cylinder BSAI125X75S the Right Clamp-Lock?
Choose this 125 mm bore when a heavy load demands extreme holding capacity, stepping up from the 80 mm bore (which provides 2513 N thrust and 3600 N holding force). If your application only requires the cylinder to remain fixed at the fully extended or retracted end of its stroke, a plain SAIL stroke-end lock would suffice; the BSAI is specifically necessary when you must freeze the load at an intermediate point. For tasks needing no lock at all, a standard SAI cylinder offers equivalent thrust without the clamping hardware.
When integrating this replacement, match the single-rod geometry, 125 mm bore, 75 mm stroke, and PT port threads. The mounting footprint accepts Basic, FA, FB, CA, CB, CR, LB, TC, TCM1, and TCM2 brackets. The robust M27x2 rod thread and 32 mm rod diameter excel at carrying high side loads, though any stroke exceeding 300 mm still warrants an external guide. Safety dictates that the clamp locks only after the rod has stopped—it cannot brake a moving load—and you must balance the air pressure before unlocking to prevent the rod from jumping abruptly. Human-safety applications require an independent mechanical 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 BSAI125X75S FAQ
The integrated clamp-lock provides a static holding force of 8600 N. It engages via spring pressure to hold the rod at any position along the stroke, operating completely independently from the 6136 N pneumatic thrust.
The clamp locks only after the cylinder has stopped and cannot brake a moving rod. To release it safely, you must apply 0.15-0.7 MPa of air to the G1/8 enclasp port while ensuring the pressures on both sides of the piston are balanced; otherwise, the rod may jump abruptly.
Related AirTAC Lock & Standard Cylinders
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