Airtac SAILB Rear Lock Cylinder SAILB40X150S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB40X150S is a genuine double-acting ISO 15552 profile cylinder with a Ø40mm bore, 150mm 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
- Stroke150 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM12×1.25
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB40X150S
The AirTAC SAILB40X150-S 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 when the piston reaches the retracted stroke end, securely holding the rod without requiring live pressure. In the 40mm bore class, it delivers a push force of 879N at 0.7MPa, making it suitable for compact holding tasks. The included magnet allows for precise position monitoring using CMSE reed or DMSE electronic sensors.
This model features a standard carbon steel rod and PT tapered port threads. The variable air cushion at the locker end is notably shorter, measuring 20mm compared to 27mm on the free end, to accommodate the locking hardware. For unlocking, you can supply air to the release port for automatic operation or use the manual override lever.
Airtac SAILB Rear Lock Cylinder SAILB40X150S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB40X150S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø40 mm |
| Stroke | 150 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 SAILB40X150S Is Used
Vertical Power-Off Hold
Prevents gravity-loaded vertical stages from dropping when air pressure is lost, securing the load at the retracted stroke end.
Safety Gate Locking
Keeps protective machine guards firmly closed and locked at the end of the cylinder stroke until pneumatic release is commanded.
Clamp and Hold
Maintains a secure clamping force on machined parts at the retracted position without continuously consuming compressed air.
Is the Airtac SAILB Rear Lock Cylinder SAILB40X150S the Right Lock Cylinder?
Choose this 40mm bore cylinder when your application requires holding a load at the retracted position during a power loss, stepping up from a plain SAI cylinder that cannot hold without live air. If your load demands greater force, the neighboring 50mm bore provides 1374N at 0.7MPa. Select this SAILB configuration specifically when the rod needs to be held in the retracted position; choose SAILF if the extended position must be secured. If your process requires locking at an arbitrary mid-stroke point rather than the stroke end, select the BSAI clamp-lock cylinder instead.
Remember that the lock is a static holding device that engages after the cylinder stops, not a dynamic brake for a moving rod. Avoid using fast-exhaust valves, as back-pressure on the locker side can unintentionally release the lock; always use an independent-exhaust solenoid valve. For safety-critical lifting applications, add an independent mechanical safety measure. This replacement requires matching the 40mm bore, 150mm stroke, back locker position, PT port, and mounting style.
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 SAILB40X150S FAQ
The 40mm bore provides a push force of 628N at 0.5MPa and 879N at 0.7MPa, with a pull force of 528N at 0.5MPa. The maximum operating pressure is 1.0MPa.
The lock is spring-applied and air-released, engaging only when the piston reaches the retracted stroke end in the back cover. It provides a static hold, not a dynamic brake, and can be unlocked automatically via air pressure or manually via a lever.
Related AirTAC Lock & Standard Cylinders
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