Airtac BSAI Locking Clamp Cylinder BSAI125X225
The AirTAC Airtac BSAI Locking Clamp Cylinder BSAI125X225 is a genuine double-acting ISO 15552 cylinder with a Ø125mm bore, 225mm 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
- Stroke225 mm
- Cylinder portG1/2
- TypeSingle rod (BSAI)
- Enclasp portG1/8
- Rod threadM27×2
About the Airtac BSAI Locking Clamp Cylinder BSAI125X225
The AirTAC BSAI125X225 is a double-acting ISO 15552 profile cylinder equipped with a spring-applied, air-released clamp-lock mechanism. A defining trait of this series is the ability to secure the load at ANY position along the 225 mm stroke, delivering a robust static holding force of 8600 N. The bidirectional clamp engages securely whether the rod was extending or retracting. Operating at 0.5 MPa, the 125 mm bore generates 6136 N of thrust, while the practical maximum thrust reaches 8590 N at 0.7 MPa. It is crucial to distinguish holding force from thrust: the 8600 N clamp rating is the capacity to hold a static load, entirely separate from the cylinder's push/pull propulsion.
This model features a 32 mm carbon steel rod with an M27x2 thread, providing substantial rigidity and high side-load tolerance. The clamping mechanism relies on a dedicated G1/8 enclasp port—a third air connection distinct from the 1/2 inch cylinder ports. To disengage the lock safely, air must be supplied to the unlock port while ensuring the pressures on both sides of the piston are balanced. The variable air cushions at the stroke ends decelerate the piston to prevent impact damage, but the cushion is never the holding device; the mechanical clamp alone holds the load. For position sensing, a magnet option (-S) can be added to interface with AirTAC CMSE reed and DMSE electronic sensors in the standard grooves.
Airtac BSAI Locking Clamp Cylinder BSAI125X225 Technical Specifications
| Model | Airtac BSAI Locking Clamp Cylinder BSAI125X225 |
|---|---|
| Series | BSAI ISO 15552 clamp-lock cylinder |
| Bore size | Ø125 mm |
| Stroke | 225 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 BSAI125X225 Is Used
Mid-Stroke Machining Hold
Secures a heavy workpiece at a precise intermediate point along the travel for machining or inspection, utilizing the 8600 N holding force to prevent deflection during the operation.
Vertical Axis Drop Prevention
Holds a vertically lifted load at any height instantly upon air loss, engaging the bidirectional clamp to prevent a catastrophic fall without relying on live air pressure.
Power Loss Safety Lock
Acts as an emergency fail-safe that freezes the rod position anywhere in the stroke during a sudden power or air supply interruption, maintaining the hold until pressures are balanced for a safe release.
Is the Airtac BSAI Locking Clamp Cylinder BSAI125X225 the Right Clamp-Lock?
Select this 125 mm bore model when an application demands extreme holding capacity that a smaller bore cannot achieve. If 8600 N of holding force exceeds your static load requirements, stepping down to a 100 mm bore offers 5500 N of holding force and 3927 N thrust at 0.5 MPa, providing a more compact and lighter solution. Conversely, the BSAI125X225 is the largest standard option in this series. Choose this clamp-lock cylinder over a plain SAI model when power-failure safety or mid-stroke positioning is mandatory. It also outperforms a SAIL cylinder, which only secures the load at the stroke ends, by gripping the rod anywhere along its travel.
When replacing a unit, verify the 125 mm bore, 225 mm stroke, PT tapered port threads, and the single-rod configuration. The correct mounting set for this single-rod profile cylinder includes Basic, FA, FB, CA, CB, CR, LB, TC, TCM1, and TCM2. Remember that the clamp locks only AFTER the cylinder has stopped; it cannot brake a moving rod. Furthermore, the lock must be released with balanced pressures to prevent the rod from jumping abruptly. If human safety depends on the hold, an additional independent mechanical safety measure is required.
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 BSAI125X225 FAQ
The BSAI125X225 provides a static holding force of 8600 N. This spring-applied, air-released clamp locks the rod at any position along the stroke. It is bidirectional, holding securely whether the rod was extending or retracting.
The clamp unlocks only when air is supplied to the G1/8 enclasp port AND the pressures on both sides of the piston are balanced. If pressures are unbalanced, the rod can jump abruptly upon release. The clamp locks only after the rod stops; it cannot brake a moving load.
Related AirTAC Lock & Standard Cylinders
Request a Quote for Airtac BSAI Locking Clamp Cylinder BSAI125X225
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.