Airtac SAILB Rear Lock Cylinder SAILB50X50S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB50X50S is a genuine double-acting ISO 15552 profile cylinder with a Ø50mm bore, 50mm 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.
- BoreØ50 mm
- Stroke50 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB50X50S
The AirTAC SAILB50X50-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 carbon steel rod, securely holding the load at the retracted stroke end without requiring live pressure. In this 50mm bore size, the cylinder generates 982N of push force and 825N of pull force at 0.5MPa, making it well-suited for medium-duty holding tasks.
This model includes a magnetic piston (-S) for precise position detection using AirTAC CMSE reed switches or DMSE solid-state electronic sensors. To accommodate the locking hardware, the variable air cushion at the locker end is 20mm, which is shorter than the 30mm cushion found on the free end. The unit operates at speeds between 30 and 800mm/s and uses PT tapered port threading.
Airtac SAILB Rear Lock Cylinder SAILB50X50S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB50X50S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø50 mm |
| Stroke | 50 mm |
| Acting type | Double acting, with lock |
| Port size | G1/4 |
| Rod thread | M16×1.5 |
| 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 (30 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 (Ø50mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 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 SAILB50X50S Is Used
Vertical Load Holding
Prevents gravity-driven drops on vertical lifts by engaging the back cover lock to hold the retracted rod position securely during power loss or pneumatic failure.
Clamp and Hold at End
Secures a workpiece at the retracted stroke terminal without consuming continuous air pressure, maintaining a stable clamping state until the release port is pressurized.
Safety Gate Hold
Keeps safety gates and heavy barriers locked in the closed position by utilizing the spring-applied lock, requiring an active air signal to release the mechanism.
Is the Airtac SAILB Rear Lock Cylinder SAILB50X50S the Right Lock Cylinder?
Select this 50mm bore cylinder when an application requires 982N of thrust at 0.5MPa, stepping down from a 63mm bore (1559N) for space efficiency, or up from a 40mm bore (628N) when higher force is necessary. Choose the SAILB configuration specifically to hold the load in the retracted position; if your process requires the rod to remain extended during a power loss, the SAILF variant is the correct choice instead. Remember that the SAIL lock is a static holding device that engages only after the piston reaches the stroke terminal, not a dynamic brake for a moving rod.
For applications requiring the load to be clamped at an arbitrary mid-stroke point rather than the stroke end, the AirTAC BSAI clamp-lock cylinder is the appropriate solution. When integrating this model, avoid using fast-exhaust valves, as back-pressure on the locker side can inadvertently release the lock; an independent-exhaust solenoid valve is required. If human safety relies on the load remaining elevated, implement an additional independent safety measure. Replacement matches require the exact 50mm bore, 50mm stroke, back locker position, PT port, and the -S magnet option.
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 SAILB50X50S FAQ
At a 0.5MPa operating pressure, the 50mm bore provides 982N of push force and 825N of pull force. At 0.7MPa, the push force increases to 1374N.
The lock is spring-applied and air-released, meaning it engages automatically when air is cut off, holding the rod securely at the retracted stroke end. It unlocks only when release air is supplied to the port or via the manual release lever.
Related AirTAC Lock & Standard Cylinders
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