Airtac SAILB Rear Lock Cylinder SAILB125X100
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB125X100 is a genuine double-acting ISO 15552 profile cylinder with a Ø125mm bore, 100mm 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
- Stroke100 mm
- Port sizeG1/2
- Lock positionBack cover
- Rod threadM27×2
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB125X100
The AirTAC SAILB125X100 is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. It generates 6136N of thrust at 0.5MPa and securely holds the rod at the retracted stroke end. The lock is spring-applied and air-released, meaning it engages automatically upon air loss to maintain your vertical load without requiring continuous live pressure.
This 125mm bore unit operates at 30-500mm/s and uses a robust 32mm carbon steel rod with PT threaded 1/2 ports. The variable air cushion at the locker end is specifically shortened to 24mm to house the locking mechanism, differentiating it from the 40mm cushion on the free end. For position sensing, adding a magnet allows the use of AirTAC CMSE reed or DMSE solid-state sensors.
Airtac SAILB Rear Lock Cylinder SAILB125X100 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB125X100 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø125 mm |
| Stroke | 100 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 SAILB125X100 Is Used
Vertical Load Safety
Secures elevated masses in the retracted position instantly upon pneumatic power loss, preventing sudden drops on vertical lifting assemblies.
End-of-Stroke Clamping
Holds workpieces firmly at the retracted terminal during machining or processing, maintaining position without consuming continuous air pressure.
Heavy Gate Holding
Locks heavy industrial gates or safety barriers securely in the closed position, utilizing the 6136N force class to resist external vibrations.
Is the Airtac SAILB Rear Lock Cylinder SAILB125X100 the Right Lock Cylinder?
Choose this 125mm bore when a 100mm bore (providing 3927N at 0.5MPa) lacks the necessary push force, or step down to an 80mm bore if 2513N is sufficient for your assembly. Select the SAILB configuration when the load must be secured in the retracted position; choose SAILF instead if the extended stroke end requires holding. If your application requires clamping at an arbitrary mid-stroke point rather than a stroke terminal, the BSAI clamp-lock cylinder is the correct solution.
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 inadvertently release the lock; always utilize an independent-exhaust solenoid valve. For human-safety critical lifting applications, implement an additional independent safety measure. Replacement matches require verifying the 125mm bore, 100mm stroke, back locker position, PT ports, and standard mounting options like FA, FB, or TC.
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 SAILB125X100 FAQ
At 0.5MPa, it provides 6136N of push force and 5734N of pull force. At 0.7MPa, the push force is 8590N, and at 0.9MPa it reaches 11045N.
The lock is spring-applied and air-released, located in the back cover to hold the rod at the retracted stroke end. It engages automatically when air pressure is lost and is released by supplying air to the release port or using the manual override.
Related AirTAC Lock & Standard Cylinders
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