Airtac SAILB Rear Lock Cylinder SAILB80X125
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB80X125 is a genuine double-acting ISO 15552 profile cylinder with a Ø80mm bore, 125mm 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.
- BoreØ80 mm
- Stroke125 mm
- Port sizeG3/8
- Lock positionBack cover
- Rod threadM20×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB80X125
The AirTAC SAILB80X125 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the back cover. This lock engages automatically to hold the rod securely at the retracted stroke end whenever the release air is cut, ensuring loads remain safely in place without consuming live pressure. Delivering 2513N of push force and 2268N of pull force at 0.5MPa, it handles heavy vertical loads with ease.
Unlike a plain SAI cylinder, this model provides true power-loss safety. The variable air cushion decelerates the piston near the stroke terminals, but the lock itself performs the actual holding. Note that the cushion at the locker end is shorter (22.5mm) compared to the free end (36mm). For position sensing, adding an -S magnet allows the use of AirTAC CMSE reed or DMSE electronic solid-state switches in the dual sensor grooves.
Airtac SAILB Rear Lock Cylinder SAILB80X125 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB80X125 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø80 mm |
| Stroke | 125 mm |
| Acting type | Double acting, with lock |
| Port size | G3/8 |
| Rod thread | M20×1.5 |
| 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 (36 mm free end / 22.5 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 (Ø80mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 2513 N | 2268 N |
| 0.7 MPa | 3519 N | — |
| Max (@1.0 MPa) | 513 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 SAILB80X125 Is Used
Vertical Lift Safety
Secures elevated loads in the retracted position during a power loss, preventing sudden drops on lifting platforms.
Conveyor Hold
Locks a retractable stopper pin in the back position to hold items on the line without continuous air consumption.
Gate Guarding
Holds a safety gate cylinder closed under load, releasing only when the release port receives air pressure.
Is the Airtac SAILB Rear Lock Cylinder SAILB80X125 the Right Lock Cylinder?
Choose this 80mm bore when a 63mm cylinder (1559N push at 0.5MPa) lacks the thrust for your vertical lift, but a 100mm bore (3927N) would be excessive. Select the SAILB configuration specifically when the load must be secured in the retracted position; if you need to hold the rod out, the SAILF variant is required. Keep in mind the lock is a static holding device that engages only after the piston stops at the stroke end, not a dynamic brake for a moving rod.
If your application requires clamping at an arbitrary mid-stroke point rather than the terminal end, the BSAI clamp-lock cylinder is the correct choice. To maintain lock integrity, never use a fast-exhaust valve, as back-pressure on the locker side can unintentionally release the mechanism; an independent-exhaust solenoid valve is mandatory. For safety-critical lifting applications, always add an independent mechanical safety measure. Replacement specs: 80mm bore, 125mm stroke, PT 3/8 port, carbon steel rod with M20x1.5 thread, and standard mountings including FA, FB, TC, and LB.
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 SAILB80X125 FAQ
At 0.5MPa operating pressure, the SAILB80X125 generates 2513N of push force and 2268N of pull force. At 0.7MPa, the push force increases to 3518N.
The lock is spring-applied and air-released, located in the back cover to hold the rod only at the retracted stroke end. It engages statically after the cylinder stops and is released automatically via air pressure or manually via a lever.
Related AirTAC Lock & Standard Cylinders
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