Airtac BSAI Locking Clamp Cylinder BSAI125X50S
The AirTAC Airtac BSAI Locking Clamp Cylinder BSAI125X50S is a genuine double-acting ISO 15552 cylinder with a Ø125mm bore, 50mm 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
- Stroke50 mm
- Cylinder portG1/2
- TypeSingle rod (BSAI)
- Enclasp portG1/8
- Rod threadM27×2
About the Airtac BSAI Locking Clamp Cylinder BSAI125X50S
The AirTAC BSAI125X50-S is a double-acting ISO 15552 profile cylinder equipped with a spring-applied, air-released clamp-lock mechanism. It secures the carbon steel piston rod at any position along its 50mm travel, delivering a massive static holding force of 8600 N. Because it features a 125mm bore, the cylinder generates 6136 N of push thrust at 0.5 MPa (8590 N at the 0.7 MPa maximum). Buyers must distinguish this holding force from thrust: the clamp sustains static loads independently of the 6136 N pneumatic push, so you size the hold against the load, not the cylinder thrust.
This unit operates at 0.15-0.7 MPa and includes a third G1/8 enclasp port—separate from the 1/2 inch PT cylinder ports—to release the lock. The integrated variable air cushion decelerates the piston near stroke ends, but the clamp is the true load-holder. An -S magnet enables position detection via AirTAC CMSE reed or DMSE electronic solid-state sensors. The clamp locks only after the rod stops and requires balanced piston pressures to unlock safely, preventing abrupt rod jumps.
Airtac BSAI Locking Clamp Cylinder BSAI125X50S Technical Specifications
| Model | Airtac BSAI Locking Clamp Cylinder BSAI125X50S |
|---|---|
| Series | BSAI ISO 15552 clamp-lock cylinder |
| Bore size | Ø125 mm |
| Stroke | 50 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 BSAI125X50S Is Used
Machining Position Hold
Clamps a heavy workpiece securely at an exact intermediate point for machining or inspection, utilizing the 8600 N holding force without relying on continuous pneumatic pressure.
Vertical Axis Drop Prevention
Locks a vertical load instantly at any height when air pressure drops, preventing gravity-driven falls on heavy lifting jigs.
Emergency Power-Loss Hold
Spring-applied mechanism engages automatically upon air loss to freeze the rod mid-stroke, protecting equipment during sudden outages.
Is the Airtac BSAI Locking Clamp Cylinder BSAI125X50S the Right Clamp-Lock?
Select this 125mm bore model when a process demands extreme intermediate stopping power, stepping down to an 80mm bore reduces the holding force to 3600 N and push thrust to 2513 N at 0.5 MPa. Choose BSAI over a SAIL cylinder when you must enclasp the load at any point in the stroke, rather than only at the end. If no intermediate hold is required, a plain SAI cylinder suffices. For safety-critical loads, remember this clamp cannot brake a moving rod and needs an independent safety measure.
This BSAI125X50-S replaces any single-rod ISO 15552 cylinder of identical bore and stroke with PT ports. It accepts Basic, FA, FB, CA, CB, CR, LB, TC, TCM1, and TCM2 mounts. The robust M27x2 rod thread handles high side loads, though external guidance is recommended for heavy tooling. The balanced-pressure unlock requirement is vital for safe operation.
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 BSAI125X50S FAQ
The clamp-lock provides a static holding force of 8600 N. It is bidirectional and locks the rod at any position along the stroke, but it only engages after the cylinder has stopped moving.
The clamp uses a third G1/8 enclasp port and requires balanced air pressure on both sides of the piston to unlock. If pressures are not balanced, the rod can move abruptly upon release, so always ensure the cylinder has stopped before unlocking.
Related AirTAC Lock & Standard Cylinders
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