Airtac SAILB Rear Lock Cylinder SAILB40X225S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB40X225S is a genuine double-acting ISO 15552 profile cylinder with a Ø40mm 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.
- BoreØ40 mm
- Stroke225 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM12×1.25
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB40X225S
The AirTAC SAILB40X225-S is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. Because it carries the -S suffix, it includes a magnet for position sensing and works seamlessly with AirTAC CMSE reed switches and DMSE solid-state electronic sensors. The lock is spring-applied and air-released, meaning it engages automatically when the piston reaches the retracted stroke end, holding the load securely without live pressure.
This 40mm bore generates 628N of push force at 0.5MPa, utilizing a 16mm carbon steel rod and a 1/4 PT port. A critical design detail is the variable air cushion: the locker-end cushion is shorter at 20mm compared to the 27mm cushion on the free end. Remember that the lock provides static holding only after the rod stops; it is not a dynamic mid-stroke brake.
Airtac SAILB Rear Lock Cylinder SAILB40X225S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB40X225S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø40 mm |
| Stroke | 225 mm |
| Acting type | Double acting, with lock |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| 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 (27 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 (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 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 SAILB40X225S Is Used
Vertical Power-Off Hold
Secures a lifted vertical load at the retracted stroke end automatically when air pressure drops, preventing sudden drops.
End-of-Stroke Clamp
Holds a workpiece firmly in place at the retracted position without consuming continuous compressed air.
Safety Gate Hold
Keeps safety gates or heavy guards locked closed at the stroke end until the release air is supplied.
Is the Airtac SAILB Rear Lock Cylinder SAILB40X225S the Right Lock Cylinder?
Choose this 40mm bore when your application requires 628N of push force at 0.5MPa; step up to a 50mm bore if you need 982N. Select the SAILB configuration to hold the load at the retracted stroke end, and pick SAILF instead if you must hold the rod at the extended position. If your machine requires locking at an arbitrary mid-stroke point rather than the end, use the BSAI clamp-lock cylinder instead.
For safe operation, do not use a fast-exhaust valve with this cylinder, as back-pressure on the locker side can unintentionally release the lock; always use an independent-exhaust solenoid valve. The lock holds statically at the stroke end only, so if human safety depends on the load staying up, add an independent safety measure. Replacement requires matching the 40mm bore, 225mm stroke, back locker position, 1/4 PT port, and -S magnet. With a 225mm stroke, ensure external guides support side loads.
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 SAILB40X225S FAQ
At 0.5MPa, this 40mm bore cylinder provides 628N of push force and 528N of pull force. At 0.7MPa, the push force increases to 879N.
The lock is spring-applied and air-released, engaging statically only when the piston reaches the retracted stroke end. It does not clamp at mid-stroke. Unlock is automatic via air supply or manual override lever.
Related AirTAC Lock & Standard Cylinders
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