Airtac SAILB Rear Lock Cylinder SAILB40X350
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB40X350 is a genuine double-acting ISO 15552 profile cylinder with a Ø40mm bore, 350mm 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
- Stroke350 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM12×1.25
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB40X350
The AirTAC SAILB40X350 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the back cover. Because the lock resides in the back, it engages when the piston reaches the retracted stroke end, securely holding the rod in the rod-in position without requiring live air pressure. The 40mm bore generates 879N of push force at 0.7MPa, making it well-suited for lighter load-holding tasks.
This extruded aluminum profile cylinder includes a variable air cushion at both ends, but the cushion length at the locker end is notably shorter at 20mm compared to the 27mm on the free end. The standard carbon steel rod features an M12x1.25 thread and a 1/4 PT port. To release the locked load, you can either supply air to the dedicated release port for automatic operation or use the manual release lever.
Airtac SAILB Rear Lock Cylinder SAILB40X350 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB40X350 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø40 mm |
| Stroke | 350 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 SAILB40X350 Is Used
Vertical Power-Off Hold
Secures a lifted vertical load in the fully retracted position instantly when air pressure is lost, preventing sudden drops.
End-Stroke Clamp
Holds a workpiece firmly at the retracted stroke end during a machining cycle without consuming continuous compressed air.
Gate Safety Stop
Maintains a raised conveyor gate in the closed retracted state during power loss, requiring an air signal to unlock.
Is the Airtac SAILB Rear Lock Cylinder SAILB40X350 the Right Lock Cylinder?
Choose this 40mm bore cylinder when you need 879N of push force at 0.7MPa; if your application requires less force, step down is not an option in the SAIL range, but if you need significantly more holding power, consider the 50mm bore which provides 1374N at 0.7MPa. Select the SAILB configuration when the load must be secured in the retracted position, and choose a SAILF model instead if the extended rod-out position requires holding. If your process demands locking at an arbitrary mid-stroke point rather than a stroke end, the BSAI clamp-lock cylinder is the correct choice.
For reliable operation, avoid using fast-exhaust valves with this lock cylinder, as back-pressure on the locker side can unintentionally release the lock; always use an independent-exhaust solenoid valve. Because this model features a 350mm stroke, adding an external guide is recommended to prevent excessive side-load wear on the rod and seals. If human safety depends on the load staying up, always add an independent safety measure alongside the lock.
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 SAILB40X350 FAQ
At an operating pressure of 0.7MPa, the 40mm bore provides 879N of push force and 528N of pull force at 0.5MPa. The maximum operating pressure is 1.0MPa.
The lock is spring-applied and air-released, engaging statically only when the rod reaches the retracted stroke end. It does not clamp at mid-stroke or act as a dynamic brake. Unlocking is achieved automatically via an air signal to the release port or manually via the release lever.
Related AirTAC Lock & Standard Cylinders
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