Airtac SAILB Rear Lock Cylinder SAILB50X175
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB50X175 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 SAILB50X175
The AirTAC SAILB50X175 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 safely holds a load in the rod-in position without requiring continuous live air pressure. In this 50mm bore class, the cylinder generates 982N of push thrust and 825N of pull thrust at 0.5 MPa, making it well-suited for medium-force vertical holding tasks.
A standard carbon steel rod provides durable service, while pneumatic cushioning absorbs end-of-stroke kinetic energy. Note that the variable air cushion at the locker end is 20mm, which is shorter than the 30mm cushion found on the free end. The lock itself is a static holding device, meaning it engages only after the cylinder has fully stopped, rather than acting as a dynamic brake to decelerate a moving rod.
Airtac SAILB Rear Lock Cylinder SAILB50X175 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB50X175 |
|---|---|
| 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 SAILB50X175 Is Used
Vertical Load Hold
Secures elevated loads in the retracted position during a power loss, preventing sudden drops in lifting mechanisms.
Clamp-and-Hold
Maintains consistent clamping force at the rod-in stroke end without consuming continuous compressed air.
Safety Gate Locking
Keeps heavy safety gates or machine guards firmly closed and locked at the retracted terminal until an air signal releases the pin.
Is the Airtac SAILB Rear Lock Cylinder SAILB50X175 the Right Lock Cylinder?
Choose this 50mm bore model when an application requires approximately 982N of push force at 0.5 MPa and a fail-safe hold at the retracted position. If your mechanism demands less force, the 40mm bore offers 628N; if you need greater clamping power, stepping up to the 63mm bore yields 1559N. Select the SAILB configuration specifically when the load must be secured in the retracted stroke end, whereas a SAILF variant would hold the extended position. For applications requiring locking at an arbitrary mid-stroke point rather than a stroke terminal, the BSAI clamp-lock cylinder is the correct alternative.
When integrating this component, avoid using a fast-exhaust valve, as back-pressure on the locker side can unintentionally release the spring-applied lock; an independent-exhaust solenoid valve is required. To unlock the rod, supply air to the release port for automatic retraction or use the manual release lever. Although this lock holds the load without live pressure, any human-safety-critical application must include an additional independent safety measure. Replacement matches require a 50mm bore, 175mm stroke, back locker position, PT port threads, and standard mounting options like FA, FB, or TC.
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 SAILB50X175 FAQ
At 0.5 MPa operating pressure, the 50mm bore provides 982N of push thrust and 825N of pull thrust. At 0.7 MPa, the push force increases to 1374N.
The lock is spring-applied and air-released, engaging only at the retracted stroke end to provide a static hold. It does not clamp at mid-stroke. You can unlock it automatically by supplying air to the release port or manually via the release lever.
Related AirTAC Lock & Standard Cylinders
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