Airtac SAILB Rear Lock Cylinder SAILB50X225S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB50X225S is a genuine double-acting ISO 15552 profile cylinder with a Ø50mm bore, 225mm 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
- Stroke225 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB50X225S
The AirTAC SAILB50X225-S is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. Because the lock is spring-applied and air-released, it safely holds the rod at the retracted stroke end without requiring continuous live pressure. Generating 982N of push force and 825N of pull force at 0.5 MPa, it provides reliable load control. The integrated -S magnet enables direct mounting of CMSE reed and DMSE solid-state sensors along the dual-side barrel grooves.
This model features a 1/4 PT tapered port and a 20mm carbon steel rod. A critical design detail is the variable air cushion: the locker-end cushion measures 20mm, which is shorter than the 30mm cushion on the free end, ensuring proper deceleration before the lock engages. The lock itself is a static holding device, not a dynamic brake that stops a moving rod.
Airtac SAILB Rear Lock Cylinder SAILB50X225S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB50X225S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø50 mm |
| Stroke | 225 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 SAILB50X225S Is Used
Vertical Lift Hold
Secures elevated loads at the retracted stroke end automatically upon air pressure loss, preventing sudden drops in lifting rigs.
Conveyor Jam Safety
Holds the rod in the retracted position during an emergency stop or power loss to maintain conveyor lane clearance.
Clamp and Hold
Maintains a fixed retracted tooling position without consuming continuous compressed air during machining cycles.
Is the Airtac SAILB Rear Lock Cylinder SAILB50X225S the Right Lock Cylinder?
Choose this 50mm bore when 40mm bore cylinders (providing 628N push at 0.5 MPa) lack sufficient thrust, but 63mm models (1559N) are oversized. Select this SAILB configuration when your machine requires the load to be safely held at the retracted rod-in position. If your application requires clamping at an arbitrary mid-stroke point rather than the stroke end, use the BSAI clamp-lock cylinder instead. To unlock, supply air to the release port or use the manual override lever. For safety-critical lifting applications, always add an independent mechanical safety measure alongside the lock.
When ordering a replacement, verify the 225mm stroke, back locker position, 1/4 PT port thread, and the -S magnet option. Because the stroke is 225mm, ensure your guiding mechanism handles side loads to prevent premature seal wear. Crucially, do not use a fast-exhaust valve with this cylinder; an independent-exhaust solenoid valve is required because back-pressure on the locker side can unintentionally release the lock.
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 SAILB50X225S 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 spring-applied lock engages automatically when the piston reaches the retracted stroke end in the back cover, holding the load without live pressure. It unlocks by supplying air to the release port or via the manual lever. It is a static hold, not a mid-stroke clamp or dynamic brake.
Related AirTAC Lock & Standard Cylinders
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