Airtac BSAI Locking Clamp Cylinder BSAI40X400S
The AirTAC Airtac BSAI Locking Clamp Cylinder BSAI40X400S is a genuine double-acting ISO 15552 cylinder with a Ø40mm bore, 400mm 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
- Stroke400 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 BSAI40X400S
The AirTAC BSAI40X400-S is a double-acting ISO 15552 profile cylinder equipped with a spring-applied, air-released clamp-lock mechanism. It features a carbon steel piston rod and a PT tapered port thread. Unlike a standard SAI cylinder, this unit incorporates a third G1/8 enclasp port dedicated to unlocking the clamp. It delivers a push thrust of 628 N at 0.5 MPa, while the integrated gripper provides a static holding force of 900 N.
It is vital to distinguish holding force from cylinder thrust: the 900 N clamp rating is the static load capacity of the brake, entirely separate from the 628 N dynamic thrust. The clamp locks the rod at any position bidirectionally, but it functions only after the cylinder has stopped; it cannot brake a moving rod. Furthermore, the variable air cushion at the stroke ends only decelerates the piston and does not contribute to holding the load. Unlocking requires balanced air pressure on both sides of the piston to prevent abrupt rod movement.
Airtac BSAI Locking Clamp Cylinder BSAI40X400S Technical Specifications
| Model | Airtac BSAI Locking Clamp Cylinder BSAI40X400S |
|---|---|
| Series | BSAI ISO 15552 clamp-lock cylinder |
| Bore size | Ø40 mm |
| Stroke | 400 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 BSAI40X400S Is Used
Vertical Axis Holding
Secures a 40mm bore vertical payload at any point in its 400mm travel, using the 900 N static clamp to prevent uncommanded drops during air pressure loss.
Machining Position Lock
Freezes the carbon steel rod mid-stroke to present a workpiece rigidly to a cutting tool, ensuring the load is held independently of the 628 N thrust.
Power Loss Safety
Engages the spring-applied clamp instantly when the air supply drops, locking the cylinder exactly where it stopped to protect operators and tooling.
Is the Airtac BSAI Locking Clamp Cylinder BSAI40X400S the Right Clamp-Lock?
Select this 40mm bore model when an application requires position holding mid-stroke rather than only at the end of travel, making it superior to a SAIL stroke-end lock. If your load requires less holding capacity, the 32mm bore offers a 600 N hold and 402 N thrust at 0.5 MPa; if you need more stability, stepping up to the 50mm bore provides a 1400 N hold and 982 N thrust. For applications that only need dynamic movement without static holding, a plain SAI cylinder suffices.
This 400mm stroke variant uses a 16mm carbon steel rod with an M12x1.25 thread, offering good side-load resistance, though at 400mm of travel an external guide rail is recommended to prevent rod deflection. The operating pressure is 0.15-0.7 MPa. For replacements, match the single-rod configuration, 40mm bore, 400mm stroke, PT ports, and the BSAI mounting set (Basic, FA, FB, CA, CB, CR, LB, TC, TCM1, TCM2). The included -S magnet works with AirTAC CMSE reed and DMSE solid-state sensors. Safety-critical loads require an additional independent mechanical measure, as the clamp unlocks only under balanced pressure.
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 BSAI40X400S FAQ
The 900 N holding force is the static capacity of the spring-applied clamp-lock mechanism, which is entirely separate from the 628 N dynamic thrust the cylinder generates at 0.5 MPa. The clamp holds the load at any position along the 400mm stroke, but only after the rod has stopped moving.
The clamp uses a third G1/8 enclasp port. To unlock it safely, you must apply air to balance the pressure on both sides of the piston while the cylinder is stopped. If the pressures are not balanced, the rod can jump abruptly when the clamp releases.
Related AirTAC Lock & Standard Cylinders
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