Airtac BSAI Locking Clamp Cylinder BSAI40X250S
The AirTAC Airtac BSAI Locking Clamp Cylinder BSAI40X250S is a genuine double-acting ISO 15552 cylinder with a Ø40mm bore, 250mm 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 900 N.
- BoreØ40 mm
- Stroke250 mm
- Cylinder portG1/4
- TypeSingle rod (BSAI)
- Enclasp portG1/8
- Rod threadM12×1.25
- 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 BSAI40X250S
The AirTAC BSAI40X250-S is a double-acting ISO 15552 profile cylinder featuring a built-in clamp-lock mechanism. A spring-applied, air-released gripper clamps the carbon steel piston rod to hold a load securely at any position along the 250mm stroke. It provides a static holding force of 900 N, while the cylinder itself generates 628 N of push thrust at 0.5 MPa. You must size the holding force against your static load, as the clamp capacity is entirely separate from the cylinder thrust.
This model includes a -S magnet for precise position sensing with AirTAC CMSE (reed) or DMSE (electronic) switches. The clamp requires a third G1/8 enclasp port to release the rod, operating independently from the 1/4 cylinder ports. Remember that the variable air cushions only decelerate the piston near stroke ends; the clamp is the sole device responsible for maintaining the static hold.
Airtac BSAI Locking Clamp Cylinder BSAI40X250S Technical Specifications
| Model | Airtac BSAI Locking Clamp Cylinder BSAI40X250S |
|---|---|
| Series | BSAI ISO 15552 clamp-lock cylinder |
| Bore size | Ø40 mm |
| Stroke | 250 mm |
| Type | Single rod (BSAI), double acting |
| Cylinder port | G1/4 |
| Rod thread | M12×1.25 |
| Lock type | Spring-applied, air-released clamp (any position) |
|---|---|
| Static holding force | 900 N |
| Enclasp / unlock port | G1/8 |
| Operating pressure | 0.15 – 0.7 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 800 mm/s |
| Max stroke | Up to 800 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 (Ø40 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 (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa (max) | 880 N | — |
Push/pull as tabulated. Rated to the 0.7 MPa operating maximum for this series. The clamp holding force (900 N) is separate from cylinder thrust. Size with a margin.
Where the Airtac BSAI Locking Clamp Cylinder BSAI40X250S Is Used
Vertical Axis Holding
Secures a lifted vertical load at any point in the 250mm travel, preventing drops if air pressure is lost.
Emergency Stop Safety
Maintains position during a sudden power outage, holding the workpiece steady until pressure is restored.
Machining Position Lock
Clamps the rod rigidly during intermediate inspection or light machining to prevent deflection.
Is the Airtac BSAI Locking Clamp Cylinder BSAI40X250S the Right Clamp-Lock?
Choose this BSAI40X250-S when you need to secure a load mid-stroke, a capability the stroke-end-only SAIL lock cannot provide. If your application only requires movement without intermediate holding, a plain SAI cylinder is sufficient. If the 900 N holding force is inadequate, stepping up to the 50mm bore yields 1400 N of hold and 982 N of thrust; if less force is needed, the 32mm bore offers 600 N of hold.
The clamp locks only after the rod has stopped and cannot brake a moving load. It must be unlocked with balanced air pressures to prevent the rod from jumping abruptly. For safety-critical applications, install an independent external safety measure. This single-rod configuration accepts Basic, FA, FB, CA, CB, CR, LB, TC, TCM1, and TCM2 mounts. It uses PT ports, an M12x1.25 rod thread, and operates at 0.15-0.7 MPa. Because the 250mm stroke is relatively long, use an external guide to prevent excessive side loading on the rod.
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 BSAI40X250S FAQ
The clamp-lock provides a static holding force of 900 N. It engages via a spring-applied gripper at any position along the stroke, but only after the piston has completely stopped moving.
The clamp is released by applying air to the G1/8 enclasp port. You must balance the air pressures on both sides of the piston before unlocking, otherwise the rod may move abruptly. An independent safety measure is required for human safety.
Related AirTAC Lock & Standard Cylinders
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