Airtac SAILB Rear Lock Cylinder SAILB125X600
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB125X600 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 SAILB125X600
The AirTAC SAILB125X600 is a double-acting profile cylinder with a mechanical lock built into the back cover. Dimensionally interchangeable per ISO 15552, it features a 125mm bore and 600mm stroke. A spring-applied, air-released lock engages when the piston reaches the retracted stroke end, holding the load securely without requiring live pressure. You can unlock it automatically by supplying air to the release port or by using the manual release lever.
In the 0.5 MPa range, this bore yields 6136N of pull force and 8590N of push at 0.7 MPa. The carbon steel rod is 32mm thick, paired with a PT 1/2 port. A notable design detail is the shorter variable air cushion at the locker end (24mm) compared to the free end (40mm), which accommodates the locking hardware while still decelerating the piston before engagement. The lock is a static holding device, not a dynamic brake that stops a moving rod.
Airtac SAILB Rear Lock Cylinder SAILB125X600 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB125X600 |
|---|---|
| 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 SAILB125X600 Is Used
Vertical Lift Power-Off Hold
Secures heavy elevated platforms at the retracted stroke end instantly when air pressure drops, preventing uncontrolled descent.
Heavy Pallet Stopper
Holds a loaded conveyor pallet firmly in the retracted position during power loss or maintenance cycles without needing live air.
Safety Gate Lock
Keeps heavy machine safety gates locked in the withdrawn position until the air-released lock is deliberately disengaged.
Is the Airtac SAILB Rear Lock Cylinder SAILB125X600 the Right Lock Cylinder?
Choose this 125mm bore when your application requires substantial holding force at the retracted stroke end, stepping up from the 80mm bore which offers 2268N of pull at 0.5 MPa. If your load must be clamped at an arbitrary mid-stroke position rather than held at the stroke terminal, select the BSAI clamp-lock cylinder instead. The SAILB variant specifically secures the rod-in position, whereas the SAILF variant holds the extended rod-out position.
For safety-critical vertical loads, add an independent safety measure alongside the lock. Valve selection is critical: do not use a fast-exhaust valve with this cylinder. Use an independent-exhaust solenoid valve, because back-pressure on the locker side can unintentionally release the spring-applied lock. At a 600mm stroke, ensure external guide rails are used to manage side loads and prevent rod deflection. Replacement matches require a 125mm bore, 600mm stroke, back locker position, PT 1/2 port, and your chosen mounting from the ISO 15552 set (Basic, FA, FB, CA, CB, CR, LB, TC, FTC, TCM1, TCM2).
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 SAILB125X600 FAQ
At 0.5 MPa, the push force is 6136N and the pull force is 5734N. At 0.7 MPa, the push force increases to 8590N. The maximum operating pressure is 1.0 MPa.
The lock is spring-applied and air-released, located in the back cover to hold the rod at the retracted stroke end. It engages statically after the cylinder stops and is released automatically via air supply or manually via a lever. It does not clamp at arbitrary mid-stroke points.
Related AirTAC Lock & Standard Cylinders
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