Airtac SAILB Rear Lock Cylinder SAILB50X25
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB50X25 is a genuine double-acting ISO 15552 profile cylinder with a Ø50mm bore, 25mm 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
- Stroke25 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB50X25
The AirTAC SAILB50X25 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock in its back cover. It provides 982N of push force at 0.5MPa and securely holds the rod at the retracted stroke end. This design guarantees vertical loads remain safely suspended during a pressure loss. The lock engages automatically when air is cut and releases via an air supply or manual lever.
Because the lock occupies the back cover, the cushioning at that locker end is notably shorter at 20mm compared to the 30mm cushion on the free end. Position sensing is available by adding a magnet for CMSE reed or DMSE electronic sensors. The standard carbon steel rod and PT tapered ports ensure robust, leak-free pneumatic connections.
Airtac SAILB Rear Lock Cylinder SAILB50X25 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB50X25 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø50 mm |
| Stroke | 25 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 SAILB50X25 Is Used
Vertical Lift Safety
Holds retracted vertical loads securely in place automatically upon air pressure loss or supply interruption.
Clamp and Hold
Maintains a retracted clamping position without consuming live air, ensuring stable end-of-stroke holding.
Gate Safety Lock
Prevents gravity-driven descent of safety gates by engaging the mechanical lock at the fully retracted position.
Is the Airtac SAILB Rear Lock Cylinder SAILB50X25 the Right Lock Cylinder?
Choose this 50mm bore when 40mm (628N push) is insufficient but 63mm (1559N) is oversized. Select SAILB specifically when the load must be secured at the retracted stroke end; choose SAILF if holding at the extended end is required. If your application needs the rod clamped at an arbitrary mid-stroke position, use the BSAI clamp-lock cylinder instead. The SAIL lock is a static holding device, not a dynamic brake for moving rods.
For safe operation, do not use a fast-exhaust valve, as back-pressure on the locker side can accidentally release the lock; always use an independent-exhaust solenoid valve. If human safety relies on the load staying up, add an independent mechanical safety measure. To match this replacement exactly, verify the 50mm bore, 25mm stroke, back locker position, PT port thread, and standard carbon steel rod without a magnet.
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 SAILB50X25 FAQ
At 0.5MPa operating pressure, the 50mm bore provides 982N of push force and 825N of pull force. At 0.9MPa, the push force increases to 1767N.
The lock is spring-applied and air-released, holding the rod statically at the retracted stroke end. It unlocks automatically via an air supply to the release port or manually via a lever, but it cannot hold at a mid-stroke position.
Related AirTAC Lock & Standard Cylinders
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