Airtac SAILB Rear Lock Cylinder SAILB40X450
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB40X450 is a genuine double-acting ISO 15552 profile cylinder with a Ø40mm bore, 450mm 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
- Stroke450 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM12×1.25
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB40X450
The AirTAC SAILB40X450 is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. A spring-applied, air-released mechanism engages a lock pin when the piston reaches the retracted stroke end, securely holding a 16mm carbon steel rod without requiring continuous live pressure. Delivering 879N of push force at 0.7MPa, it provides reliable power-loss safety for lighter loads.
Unlike a standard SAI unit, this model secures the load statically only at the terminal position on the locker side; it will not clamp at an arbitrary mid-stroke point. The variable air cushion at the locker end is notably shorter at 20mm compared to 27mm on the free end, ensuring compact deceleration before the lock engages. For position feedback, adding a magnet allows the use of AirTAC CMSE reed or DMSE electronic sensors along the dual-side barrel grooves.
Airtac SAILB Rear Lock Cylinder SAILB40X450 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB40X450 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø40 mm |
| Stroke | 450 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 SAILB40X450 Is Used
Vertical Lift Safety
Prevents a raised platform from crashing down during a power loss by mechanically locking the retracted rod-in position.
Pallet Stopper
Holds a stopped conveyor load securely at the end of the retraction stroke without consuming continuous air pressure.
Safety Gate Hold
Keeps a machine guard firmly closed and locked at the retracted stroke end until the release air is supplied.
Is the Airtac SAILB Rear Lock Cylinder SAILB40X450 the Right Lock Cylinder?
Choose this 40mm bore if your application requires 879N of push force at 0.7MPa, or step up to the 50mm bore for 1374N if the load demands greater thrust. Select this SAILB configuration when the load must be held safely in the retracted rod-in position; choose a SAILF variant instead if the extended rod-out position requires holding. If your process requires locking at any intermediate point along the 450mm travel, use a BSAI clamp-lock cylinder rather than this stroke-end model.
Because the SAIL lock is a static holding device that engages after the cylinder stops, it cannot brake a moving rod. Never 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. For human-safety critical loads, add an independent mechanical safety measure. At 450mm stroke, guide the load carefully to prevent excessive side loads on the rod. Replacement match: 40mm bore, 450mm stroke, back locker, PT ports, standard mounting (Basic, FA, FB, TC, etc.), no 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 SAILB40X450 FAQ
At 0.7MPa, this 40mm bore cylinder provides 879N of push force and 528N of pull force. At the maximum 1.0MPa operating pressure, it delivers up to 128kgf.
The lock is spring-applied and air-released, engaging only after the piston reaches the retracted stroke end in the back cover. It is a static hold, not a mid-stroke clamp or dynamic brake. Unlock it automatically by supplying release air, or use the manual release lever.
Related AirTAC Lock & Standard Cylinders
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