Airtac BSAI Locking Clamp Cylinder BSAI125X25S
The AirTAC Airtac BSAI Locking Clamp Cylinder BSAI125X25S is a genuine double-acting ISO 15552 cylinder with a Ø125mm bore, 25mm 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
- Stroke25 mm
- Cylinder portG1/2
- TypeSingle rod (BSAI)
- Enclasp portG1/8
- Rod threadM27×2
About the Airtac BSAI Locking Clamp Cylinder BSAI125X25S
The AirTAC BSAI125X25-S is a double-acting ISO 15552 extruded-profile cylinder equipped with a spring-applied, air-released clamp-lock. It secures the load at any position along its 25 mm travel, providing a formidable static holding force of 8600 N. Because it is a single-rod design, the practical thrust is 6136 N at 0.5 MPa and 8590 N at 0.7 MPa. Buyers must distinguish this holding force from thrust: the clamp resists an external static load, whereas thrust dictates the cylinder's motive capability.
This model uses a 32 mm carbon steel rod with an M27x2 thread, providing exceptional rigidity against side loads. The clamping mechanism requires a separate G1/8 enclasp port and operates only after the piston has stopped; it cannot brake a moving rod. Furthermore, unlocking demands balanced air pressure on both piston sides to prevent the rod from jumping abruptly. The integrated variable air cushion decelerates the piston near stroke ends, but the clamp is the true load holder.
Airtac BSAI Locking Clamp Cylinder BSAI125X25S Technical Specifications
| Model | Airtac BSAI Locking Clamp Cylinder BSAI125X25S |
|---|---|
| Series | BSAI ISO 15552 clamp-lock cylinder |
| Bore size | Ø125 mm |
| Stroke | 25 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 BSAI125X25S Is Used
Vertical Load Arrest
Secures heavy vertical payloads at any point in the 25 mm travel, holding up to 8600 N without relying on continuous air pressure.
Power-Loss Safety Hold
Prevents gravity-driven drops during air or power loss. The spring-applied clamp engages instantly once the cylinder stops moving.
Machining Position Lock
Locks a heavy workpiece rigidly in place for machining or inspection, ensuring the 32 mm rod and clamp resist cutting vibrations.
Is the Airtac BSAI Locking Clamp Cylinder BSAI125X25S the Right Clamp-Lock?
Select this 125 mm bore when an application demands extreme mid-stroke holding power that a stroke-end-only SAIL cannot provide. If the 8600 N hold exceeds requirements, stepping down to the 100 mm bore offers a 5500 N hold alongside 3927 N thrust at 0.5 MPa. For simple extension without intermediate clamping, a plain SAI cylinder is sufficient. This BSAI125X25-S includes a magnet for CMSE reed and DMSE electronic sensors, uses PT tapered ports (1/2 inch cylinder, G1/8 enclasp), and accepts Basic, FA, FB, CA, CB, CR, LB, TC, TCM1, or TCM2 mounts. The robust M27x2 rod thread further enhances side-load resistance.
Remember that the clamp engages solely after the cylinder halts; it will not arrest dynamic motion. Safety-critical applications require an independent external measure. Always ensure pressures are balanced before releasing the clamp to avoid sudden rod movement.
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 BSAI125X25S FAQ
The clamp-lock provides a static holding force of 8600 N. It locks the rod at any position bidirectionally, but only after the cylinder has stopped moving; it is not a dynamic brake.
The clamp is released via the G1/8 enclasp port. You must balance the air pressure on both sides of the piston before unlocking, otherwise the rod can move abruptly. An independent safety measure is required for human safety.
Related AirTAC Lock & Standard Cylinders
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