Airtac BSAI Locking Clamp Cylinder BSAI40X250
The AirTAC Airtac BSAI Locking Clamp Cylinder BSAI40X250 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 BSAI40X250
The AirTAC BSAI40X250 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released clamp-lock mechanism. It secures the 16mm carbon steel piston rod at any position along its 250mm travel, delivering a static holding force of 900 N. Because it is an enclasp gripper acting directly on the rod, the holding force is entirely separate from the cylinder thrust, which peaks at 879 N push at 0.7 MPa; buyers must size the 900 N holding capacity against the static load rather than relying on thrust figures.
This unit operates on PT tapered ports, utilizing a 1/4 cylinder port alongside a dedicated G1/8 enclasp port for the unlock air. The clamp engages bidirectionally only after the rod has come to a complete stop, meaning it cannot brake a moving load. To prevent the rod from jumping abruptly upon release, the mechanism must be unlocked only when air pressures on both sides of the piston are balanced. Additionally, the variable air cushions at the stroke ends merely decelerate the piston; the clamp itself is what holds the load securely in place.
Airtac BSAI Locking Clamp Cylinder BSAI40X250 Technical Specifications
| Model | Airtac BSAI Locking Clamp Cylinder BSAI40X250 |
|---|---|
| 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 BSAI40X250 Is Used
Vertical Axis Holding
Maintains a 900 N grip on the rod at any intermediate height on vertical lifts, preventing gravity-driven drops when air pressure is removed.
Machining Position Lock
Freezes the workpiece carriage securely mid-stroke during drilling or milling operations, isolating the load from cylinder thrust fluctuations.
Power Loss Safety
The spring-applied clamp engages automatically upon air loss, holding the load exactly where it stopped rather than letting it drift to the stroke end.
Is the Airtac BSAI Locking Clamp Cylinder BSAI40X250 the Right Clamp-Lock?
Choose this 40mm bore model when an application requires 628 N of thrust at 0.5 MPa combined with a 900 N static hold anywhere in the travel. If the load demands greater resistance, stepping up to the 50mm bore provides 982 N thrust and a 1400 N hold, whereas dropping to the 32mm bore offers 402 N thrust and a 600 N hold. Select the BSAI clamp-lock over a SAIL model when you need to secure the load mid-stroke rather than only at the end positions; a plain SAI cylinder suffices if no holding is required. This BSAI40X250 features a 1/4 PT cylinder port, a G1/8 unlock port, and accepts Basic, FA, FB, CA, CB, CR, LB, TC, TCM1, or TCM2 mounts. The 16mm rod with an M12x1.25 thread provides a robust interface for side loads, though strokes of 250mm still benefit from external guidance to prevent rod deflection. Because no magnet is specified, position sensing via CMSE or DMSE switches is not enabled.
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 BSAI40X250 FAQ
The BSAI40X250 provides a static holding force of 900 N. Its spring-applied enclasp mechanism clamps the rod bidirectionally at any position along the 250mm stroke, though it only engages after the rod has stopped moving.
The clamp is released via a G1/8 unlock port, but only when pressures on both sides of the piston are balanced to prevent the rod from jumping. Unlike a SAIL cylinder which only holds at stroke ends, this BSAI model locks anywhere, but safety-critical loads still require an independent backup measure.
Related AirTAC Lock & Standard Cylinders
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