Airtac BSAI Locking Clamp Cylinder BSAI125X900
The AirTAC Airtac BSAI Locking Clamp Cylinder BSAI125X900 is a genuine double-acting ISO 15552 cylinder with a Ø125mm bore, 900mm 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
- Stroke900 mm
- Cylinder portG1/2
- TypeSingle rod (BSAI)
- Enclasp portG1/8
- Rod threadM27×2
About the Airtac BSAI Locking Clamp Cylinder BSAI125X900
The AirTAC BSAI125X900 is a double-acting ISO 15552 profile cylinder equipped with a spring-applied, air-released clamp-lock mechanism. It delivers a substantial push thrust of 6136 N at 0.5 MPa and features a robust 32 mm carbon steel rod with an M27x2 thread. Because the clamp grips the rod directly, it secures the load at any position along the 900 mm stroke, providing a static holding force of 8600 N. It is crucial to distinguish this holding force from the cylinder thrust; you must size the clamp capacity against the static load, not the pneumatic push power.
This enclasp unit operates via a third G1/8 port, requiring 0.15-0.7 MPa to release the spring tension. The clamp is bidirectional and halts the rod securely after it stops moving, but it cannot brake a moving load. The integrated variable air cushions only decelerate the piston near the stroke ends to prevent impact damage; they do not hold the load. For safety-critical positioning, an independent external measure is required, as unlocking demands balanced pressures on both sides of the piston to prevent abrupt rod jumps.
Airtac BSAI Locking Clamp Cylinder BSAI125X900 Technical Specifications
| Model | Airtac BSAI Locking Clamp Cylinder BSAI125X900 |
|---|---|
| Series | BSAI ISO 15552 clamp-lock cylinder |
| Bore size | Ø125 mm |
| Stroke | 900 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 BSAI125X900 Is Used
Vertical Load Holding
Secures heavy vertical loads at any point in the 900 mm travel, preventing gravity-induced drops during power loss.
Machining Position Lock
Clamps a workpiece firmly in a specific mid-stroke location for heavy machining operations without relying on air pressure.
Mid-Stroke Safety Stop
Provides a reliable 8600 N holding force anywhere along the stroke to secure a stopped load during emergency stops.
Is the Airtac BSAI Locking Clamp Cylinder BSAI125X900 the Right Clamp-Lock?
Choose this 125 mm bore model when a smaller bore, such as the 100 mm version offering 3927 N thrust and 5500 N holding force, cannot safely support your static load. If your application only requires holding at the stroke extremes, a plain SAI cylinder or SAIL end-lock suffices, but the BSAI is necessary for mid-stroke clamping. For this 900 mm stroke, the large 32 mm rod and M27x2 thread provide excellent side-load resistance, yet an external guide rail is still recommended for such a long unsupported length.
When replacing a unit, verify the single-rod configuration, 125 mm bore, 900 mm stroke, and PT-threaded ports. The 1/2 inch cylinder ports and G1/8 enclasp port must be correctly plumbed. This model supports Basic, FA, FB, CA, CB, CR, LB, TC, TCM1, and TCM2 mounts. Without the -S magnet option, it cannot host CMSE reed or DMSE electronic sensors. Remember the clamp locks only after the cylinder stops and requires balanced pressure to unlock safely.
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 BSAI125X900 FAQ
The clamp-lock mechanism provides a static holding force of 8600 N. It grips the 32 mm rod at any position along the 900 mm stroke, holding the load securely without continuous air pressure, provided the rod has already stopped moving.
The clamp uses a spring-applied, air-released mechanism via a third G1/8 port. To prevent the rod from jumping abruptly, the air pressures on both sides of the piston must be balanced before unlocking. It is not a dynamic brake and only locks after the cylinder stops.
Related AirTAC Lock & Standard Cylinders
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