Airtac SAILB Rear Lock Cylinder SAILB50X800
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB50X800 is a genuine double-acting ISO 15552 profile cylinder with a Ø50mm bore, 800mm 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
- Stroke800 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB50X800
The AirTAC SAILB50X800 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the back cover. It securely holds the rod at the retracted stroke end, delivering 982N of push force at 0.5 MPa. The carbon steel rod and PT tapered ports make it a robust choice for pneumatic automation.
Unlike a plain SAI cylinder, this SAIL model retains the load without live air pressure. The lock engages statically after the piston stops, and you can release it automatically via air or manually. Note that the variable air cushion at the locker end is 20mm, shorter than the 30mm cushion on the free end, specifically accommodating the locking mechanism.
Airtac SAILB Rear Lock Cylinder SAILB50X800 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB50X800 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø50 mm |
| Stroke | 800 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 SAILB50X800 Is Used
Vertical Load Holding
Secures elevated loads in the retracted position during a power loss, preventing sudden drops until air pressure is restored to release the lock.
Conveyor Lift Stops
Holds a lowered diverter or gate firmly at the rod-in stroke end to maintain lane alignment without continuously consuming compressed air.
Power Failure Safety
Acts as a fail-safe lock on safety doors or machine guards, keeping equipment securely closed when the pneumatic system is depressurized.
Is the Airtac SAILB Rear Lock Cylinder SAILB50X800 the Right Lock Cylinder?
Choose this 50mm bore when an application requires 982N push force at 0.5 MPa and safe load holding at the retracted position. If your system requires less force, the 40mm bore provides 628N; if you need more, the 63mm bore offers 1559N. Select SAILB to hold the rod-in position, or SAILF to hold the extended position. If you need to clamp the rod at an arbitrary mid-stroke point rather than the stroke end, use the BSAI clamp-lock cylinder instead.
This lock is a static holding device, not a dynamic brake for a moving rod. Avoid using fast-exhaust valves, as back-pressure on the locker side can unintentionally release the lock; use an independent-exhaust solenoid valve instead. For safety-critical loads that could injure operators if they drop, always add an independent mechanical safety measure. When replacing, match the 50mm bore, 800mm stroke, back locker position, PT port thread, and standard carbon steel rod. Because this stroke is 800mm, ensure adequate side-load support and use a guide rail to prevent rod bending.
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 SAILB50X800 FAQ
At 0.5 MPa operating pressure, the 50mm bore provides 982N of push force and 825N of pull force. At 0.7 MPa, the push force increases to 1374N.
The spring-applied, air-released lock engages statically when the rod reaches the retracted stroke end in the back cover. It holds the load without live pressure and unlocks via automatic air supply or a manual release lever. It does not clamp at mid-stroke.
Related AirTAC Lock & Standard Cylinders
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