Airtac SAILB Rear Lock Cylinder SAILB125X600S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB125X600S is a genuine double-acting ISO 15552 profile cylinder with a Ø125mm bore, 600mm 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
- Stroke600 mm
- Port sizeG1/2
- Lock positionBack cover
- Rod threadM27×2
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB125X600S
The AirTAC SAILB125X600-S is a double-acting ISO 15552 profile cylinder equipped with a spring-applied, air-released mechanical lock housed in the back cover. Because the lock engages only when the piston reaches the retracted stroke end, it securely holds a 125mm bore load in place without requiring continuous live air pressure. At 0.5 MPa this size generates 6136N of push force and 5734N of pull force, making it suitable for heavy-duty positioning tasks.
This model includes a magnetic piston (-S) for position sensing with AirTAC CMSE reed and DMSE electronic switches. To accommodate the locking hardware, the variable air cushion at the locker end is 24mm, which is shorter than the 40mm cushion found on the opposite free end. The standard carbon steel rod features an M27x2 thread, and the unit operates effectively at speeds between 30 and 500 mm/s.
Airtac SAILB Rear Lock Cylinder SAILB125X600S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB125X600S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø125 mm |
| Stroke | 600 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 SAILB125X600S Is Used
Vertical Load Holding
Secures elevated masses in the retracted position during a power loss or air pressure drop, preventing sudden drops on lifting rigs.
Pallet Arrestor
Holds a conveyor pallet firmly at the retracted stroke end while work is performed, releasing automatically only when air is supplied.
Clamp and Hold
Maintains heavy machining fixtures locked in the retracted terminal position without consuming continuous compressed air.
Is the Airtac SAILB Rear Lock Cylinder SAILB125X600S the Right Lock Cylinder?
Choose this 125mm bore over the 100mm option when you need to step up from 3927N to 6136N of push force at 0.5 MPa, or drop down to the 160mm bore if your application requires 10053N. Select the SAILB configuration when the load must be secured in the retracted position, and pick SAILF instead if the extended stroke end needs to be held. If your process requires clamping at an arbitrary mid-stroke point rather than a terminal position, the BSAI clamp-lock cylinder is the correct alternative.
For a 600mm stroke, adding an external guide mechanism is recommended to manage side loads and prevent rod wear. Remember that this 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; utilize an independent-exhaust solenoid valve instead. If human safety depends on the load remaining retracted, implement an independent mechanical safety measure as a backup.
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 SAILB125X600S FAQ
At 0.5 MPa, the 125mm bore provides 6136N of push force and 5734N of pull force. At 0.7 MPa, the push force increases to 8590N.
The spring-applied lock engages automatically when the rod reaches the retracted stroke end, holding the load without live pressure. It unlocks by supplying air to the release port or by using the manual release lever.
Related AirTAC Lock & Standard Cylinders
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