Airtac SAILB Rear Lock Cylinder SAILB40X500S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB40X500S is a genuine double-acting ISO 15552 profile cylinder with a Ø40mm bore, 500mm stroke and a built-in spring-applied, air-released mechanical lock in the back cover — it holds the load at the retracted (rod-in) stroke end even when air is lost.
- BoreØ40 mm
- Stroke500 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM12×1.25
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB40X500S
The AirTAC SAILB40X500-S is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. Because the lock is spring-applied and air-released, cutting the release air automatically drives a lock pin into the 16mm carbon steel rod, securely holding the load at the retracted stroke end without requiring live pressure. At 0.5 MPa it provides 628N of push and 528N of pull force, making it well-suited for compact power-failure safety applications.
This -S variant includes a magnet for position sensing and works seamlessly with AirTAC CMSE reed and DMSE solid-state switches. To accommodate the locking hardware, the variable air cushion at the locker end is shorter at 20mm compared to the 27mm cushion on the free end. The lock is a static holding device that engages after the piston stops; it is not a dynamic brake, and it clamps only at the stroke terminal rather than at an arbitrary mid-stroke point.
Airtac SAILB Rear Lock Cylinder SAILB40X500S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB40X500S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø40 mm |
| Stroke | 500 mm |
| Acting type | Double acting, with lock |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| Lock type | Spring-applied, air-released (back cover) |
|---|---|
| Unlock | Automatic (air) & manual |
| Operating pressure | 0.15 – 1.0 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 800 mm/s |
| Cushion | Adjustable (27 mm free end / 20 mm lock end) |
| Max stroke | Up to 1200 mm |
Specifications follow the official AirTAC SAIL datasheet (ISO 15552). Confirm against the product label before installation. Port options: PT / G.
How the Lock Holds
The lock is spring-applied and air-released: a spring drives a lock pin into the rod when the release air is removed, so the load is held at the retracted (rod-in) stroke end without live pressure. Supply air to the release port to unlock automatically, or use the manual release lever.
The lock engages only when the piston reaches the stroke terminal on the back-cover side — it is a static end-of-stroke hold, not a mid-stroke clamp and not a moving-rod brake. For locking at any position along the stroke, choose a BSAI clamp-lock instead.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
Cylinder thrust is separate from the lock's holding capability. Actual usable force is lower than theoretical due to friction and back-pressure — size with a margin.
Where the Airtac SAILB Rear Lock Cylinder SAILB40X500S Is Used
Vertical Power-Off Hold
Secures lifted loads in the retracted position instantly when compressed air is lost, preventing sudden drops.
End-of-Stroke Clamp
Maintains positive holding force on a workpiece at the retracted terminal without consuming continuous air pressure.
Safety Gate Interlock
Keeps protective barriers and heavy doors firmly closed and locked in the retracted state during machine operation.
Is the Airtac SAILB Rear Lock Cylinder SAILB40X500S the Right Lock Cylinder?
Choose this 40mm bore when your application requires up to 528N of pull force at 0.5 MPa; if you need greater thrust, stepping up to the 50mm bore yields 825N of pull force. Select the SAILB configuration when the load must be secured in the retracted (rod-in) position, whereas a SAILF front-locker version holds the rod-out extended position. If your design requires locking at any intermediate mid-stroke point rather than solely at the end, you must use a BSAI clamp-lock cylinder instead.
For reliable operation, never use a fast-exhaust valve with this lock cylinder; always select an independent-exhaust solenoid valve, as back-pressure on the locker side can unintentionally release the lock. Since this model features a 500mm stroke, incorporating external guide rails to manage side loads and prevent rod binding is highly recommended. Ensure your replacement matches the 40mm bore, 500mm stroke, back locker position, PT tapered port threads, and -S magnet specification. If human safety depends on the load staying up, add an independent safety measure as well.
Quick checklist
- ✓ Hold needed at the retracted (rod-in) end?
- ✓ Or lock anywhere → use BSAI
- ✓ Independent-exhaust valve fitted
- ✓ Port/thread type (PT/G)
- ✓ Extra safety measure for people
Airtac SAILB Rear Lock Cylinder SAILB40X500S FAQ
At an operating pressure of 0.5 MPa, this 40mm bore cylinder generates 628N of push force and 528N of pull force. At 0.7 MPa, the push force increases to 879N.
The lock is spring-applied and air-released, meaning it engages automatically at the retracted stroke end when air is cut off. To unlock the rod, you supply air to the release port or use the manual release lever. It functions as a static hold only, not a mid-stroke clamp or dynamic brake.
Related AirTAC Lock & Standard Cylinders
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