Airtac SAILB Rear Lock Cylinder SAILB125X160
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB125X160 is a genuine double-acting ISO 15552 profile cylinder with a Ø125mm bore, 160mm 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.
- BoreØ125 mm
- Stroke160 mm
- Port sizeG1/2
- Lock positionBack cover
- Rod threadM27×2
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB125X160
The AirTAC SAILB125X160 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the back cover. This mechanism engages when the piston reaches the retracted stroke end, securely holding the rod and load without requiring continuous live air pressure. It delivers a robust 6136N push force at 0.5MPa, utilizing a 32mm carbon steel rod and a 1/2in PT port.
Unlike a plain SAI cylinder, this model provides true static load-holding upon air loss. The lock is automatically released by supplying air to the release port, or manually via a lever. Note that the variable air cushion at the locker end is 24mm, intentionally shorter than the 40mm cushion at the free end to accommodate the locking hardware. The barrel is extruded aluminum, dimensionally interchangeable per ISO 15552 mounting interfaces.
Airtac SAILB Rear Lock Cylinder SAILB125X160 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB125X160 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø125 mm |
| Stroke | 160 mm |
| Acting type | Double acting, with lock |
| Port size | G1/2 |
| Rod thread | M27×2 |
| 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 – 500 mm/s |
| Cushion | Adjustable (40 mm free end / 24 mm lock end) |
| Max stroke | Up to 1500 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 (Ø125mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 6136 N | 5734 N |
| 0.7 MPa | 8590 N | — |
| Max (@1.0 MPa) | 1251 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 SAILB125X160 Is Used
Vertical Lift Holding
Secures elevated loads in the retracted position instantly if air pressure drops, preventing sudden descents on heavy vertical actuators.
Power Failure Safety
Maintains a safe rod-in state during plant power outages, keeping machine guards and heavy gates closed without relying on live air.
End-of-Stroke Clamping
Locks the 32mm rod firmly at the retracted terminal to hold heavy workpieces steady during machining or processing operations.
Is the Airtac SAILB Rear Lock Cylinder SAILB125X160 the Right Lock Cylinder?
Choose this 125mm bore when 80mm falls short (80mm yields 2513N push at 0.5MPa) but 160mm is excessive (160mm yields 10053N). Select the SAILB configuration to hold loads at the rod-in position; choose SAILF instead if the extended rod-out position must be secured. If your application requires clamping at an arbitrary mid-stroke point rather than a stroke-end hold, use the BSAI clamp-lock cylinder instead.
Remember that this lock is a static holding device, not a dynamic brake for a moving rod. Valve selection is critical: never use a fast-exhaust valve, and always utilize an independent-exhaust solenoid valve, because back-pressure on the locker side can inadvertently release the lock. For safety-critical lifting applications, add an independent mechanical safety measure. Replacement specifications must match the 125mm bore, 160mm stroke, back locker position, PT port threads, and standard carbon steel rod (no -S magnet specified).
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 SAILB125X160 FAQ
At 0.5MPa operating pressure, the 125mm bore provides 6136N of push force and 5734N of pull force. At 0.7MPa, the push force increases to 8590N.
The lock is spring-applied and air-released, engaging only at the retracted stroke end to hold the load statically. It unlocks automatically via air supply to the release port or manually via a lever. It does not clamp mid-stroke.
Related AirTAC Lock & Standard Cylinders
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