Airtac SAILB Rear Lock Cylinder SAILB50X500
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB50X500 is a genuine double-acting ISO 15552 profile cylinder with a Ø50mm bore, 500mm 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
- Stroke500 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB50X500
The AirTAC SAILB50X500 is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. This spring-applied, air-released lock engages automatically when the piston reaches the retracted stroke end, securely holding a 982N pull load at 0.5 MPa without requiring continuous air pressure. It combines the reliability of a standard extruded aluminum SAI body with critical power-failure safety.
Unlike a plain SAI cylinder, this model ensures your load stays put during pressure loss. The lock is a static holding device, not a dynamic brake for a moving rod. For end-of-stroke sensing, you can add a magnet and CMSE reed or DMSE solid-state sensors to the dual side grooves. Note that the variable air cushion at the locker end is 20mm, which is shorter than the 30mm cushion found on the free end.
Airtac SAILB Rear Lock Cylinder SAILB50X500 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB50X500 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø50 mm |
| Stroke | 500 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 SAILB50X500 Is Used
Vertical Lift Hold
Prevents a raised vertical load from dropping when shop air pressure is suddenly lost, holding the rod securely at the retracted end.
Pallet Stop
Locks a diverter or stopper block in the retracted position during conveyor idle times, ensuring the path stays clear without live air.
Safety Guard Lock
Keeps a safety guard or heavy gate securely closed and retracted during machine maintenance until release air is actively supplied.
Is the Airtac SAILB Rear Lock Cylinder SAILB50X500 the Right Lock Cylinder?
Choose this 50mm bore when you need 982N of pull force at 0.5 MPa and must secure a load at the rod-in position. If your application requires less force, the 40mm bore provides 528N pull; if you need more, the 63mm bore offers 1402N. Select SAILB specifically when the retracted position is the safe state; choose SAILF instead if the extended position must be held. If your machine requires locking at an arbitrary mid-stroke point rather than the stroke end, select the BSAI clamp-lock cylinder instead.
Always use an independent-exhaust solenoid valve, as a fast-exhaust valve can create back-pressure on the locker side and accidentally release the lock. Because this unit has a 500mm stroke, mounting it with a front or rear foot bracket and using external guide rails is highly recommended to prevent excessive side-load wear on the carbon steel rod and seals. For any safety-critical lifting application, add an independent mechanical safety device as well.
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 SAILB50X500 FAQ
At a 0.5 MPa operating pressure, this 50mm bore cylinder provides 982N of push force and 825N of pull force. At the maximum 1.0 MPa pressure, it achieves 200 kgf.
The lock is spring-applied and air-released. It engages statically when the piston reaches the retracted stroke end, holding the load without live pressure. To unlock, you supply air to the release port or use the manual release lever.
Related AirTAC Lock & Standard Cylinders
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