Airtac SAILB Rear Lock Cylinder SAILB40X225
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB40X225 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 SAILB40X225
The AirTAC SAILB40X225 is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock inside the back cover. A spring-applied, air-released mechanism engages when the piston reaches the retracted stroke end, securing the load without relying on live air pressure. In the 40mm bore class, it generates 628N of push force and 528N of pull force at 0.5 MPa.
This unit features a carbon steel piston rod and PT tapered port threads. The variable air cushion at the locker end is notably shorter at 20mm compared to 27mm on the free end, a specific design accommodation for the locking hardware. The lock releases automatically via air supply or manually via a lever, but avoid fast-exhaust valves as back-pressure on the locker side can inadvertently release the pin.
Airtac SAILB Rear Lock Cylinder SAILB40X225 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB40X225 |
|---|---|
| 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 SAILB40X225 Is Used
Vertical Load Holding
Secures a lifted vertical load in the fully retracted position instantly if air pressure drops, preventing crashes on the shop floor.
End-of-Stroke Clamp
Maintains a solid mechanical hold on a workpiece at the rod-in stroke end without continuously consuming compressed air.
Gate Safety Locking
Keeps safety gates and access doors firmly closed and locked at the retracted terminal until the release air is actively supplied.
Is the Airtac SAILB Rear Lock Cylinder SAILB40X225 the Right Lock Cylinder?
Choose this 40mm bore when an application requires safely holding a retracted load during a power loss, as it provides 628N of thrust at 0.5 MPa. If your setup requires a higher clamping force, stepping up to the 50mm bore yields 982N at the same pressure. Select SAILB for holding the rod-in position; choose SAILF if the extended rod-out position must be secured instead.
This lock is a static holding device that engages only after the cylinder stops at the stroke terminal, not a dynamic brake for a moving rod. It will not clamp at an arbitrary mid-stroke point; for intermediate positioning, select the BSAI clamp-lock cylinder instead. Because back-pressure can lift the lock pin, always use an independent-exhaust solenoid valve rather than a fast-exhaust valve. For any human-safety critical lifting application, add an independent mechanical safety measure. Replacement specs: 40mm bore, 225mm stroke, back locker, PT ports, and no sensor 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 SAILB40X225 FAQ
At 0.5 MPa operating pressure, the 40mm bore provides 628N of push force and 528N of pull force. At 0.7 MPa, the push force increases to 879N.
The lock is spring-applied and air-released, engaging only when the piston reaches the retracted stroke end in the back cover. It unlocks automatically via air supply or manually via a lever, but it cannot hold the rod at a mid-stroke position.
Related AirTAC Lock & Standard Cylinders
Request a Quote for Airtac SAILB Rear Lock Cylinder SAILB40X225
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.