Airtac SAILB Rear Lock Cylinder SAILB50X175S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB50X175S is a genuine double-acting ISO 15552 profile cylinder with a Ø50mm bore, 175mm 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
- Stroke175 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB50X175S
The AirTAC SAILB50X175-S is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the back cover. Because the lock engages when the piston reaches the retracted stroke end, it securely holds the rod in the power-off state. In the 50mm bore class, this actuator generates 982N of push force and 825N of pull force at 0.5 MPa, making it well-suited for moderate vertical lifting tasks.
This model includes a magnet (-S) for position sensing with AirTAC CMSE reed and DMSE electronic switches. A key design trait is that the variable air cushion at the locker end is notably shorter (20mm) than the free end cushion (30mm). The lock itself provides a static hold after the cylinder stops; it is not a dynamic brake for a moving rod, and the cushion solely decelerates the load near the stroke terminus.
Airtac SAILB Rear Lock Cylinder SAILB50X175S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB50X175S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø50 mm |
| Stroke | 175 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 SAILB50X175S Is Used
Vertical Lift Holding
Secures elevated loads in the retracted position during a power loss, preventing sudden drops without needing continuous air pressure.
Safety Gate Lock
Keeps heavy safety gates firmly locked in the closed position at the back stroke end until the air-release port is actuated.
Clamp and Hold
Maintains a static holding force on a workpiece at the end of the stroke while downstream machining operations occur.
Is the Airtac SAILB Rear Lock Cylinder SAILB50X175S the Right Lock Cylinder?
Select this 50mm bore cylinder when an application requires a reliable load hold at the rod-in position without consuming continuous live air. If your system requires a higher thrust class, stepping up to the 63mm bore yields 1559N of push force at 0.5 MPa; conversely, dropping to a 40mm bore reduces thrust to 628N. Choose this SAILB variant specifically for retracted-end holding, whereas a SAILF model holds the extended end.
If the machinery demands clamping at an arbitrary mid-stroke point rather than the stroke end, the BSAI clamp-lock cylinder is the correct choice. For this back-lock configuration, avoid using fast-exhaust valves, as back-pressure on the locker side can inadvertently release the lock—always use an independent-exhaust solenoid valve. When replacing this unit, match the 50mm bore, 175mm stroke, PT tapered port threads, and the -S magnet. Ensure the carbon steel rod is protected against side-loads by utilizing external guide rails.
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 SAILB50X175S FAQ
At 0.5 MPa operating pressure, this 50mm bore cylinder provides 982N of push force and 825N of pull force. At 0.7 MPa, the push force increases to 1374N.
The lock is spring-applied and air-released, engaging statically only when the rod reaches the retracted stroke end. It unlocks automatically via air supply to the release port or manually via a lever, but it cannot hold the rod at a mid-stroke position.
Related AirTAC Lock & Standard Cylinders
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