Airtac SAILB Rear Lock Cylinder SAILB63X25S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB63X25S is a genuine double-acting ISO 15552 profile cylinder with a Ø63mm bore, 25mm 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.
- BoreØ63 mm
- Stroke25 mm
- Port sizeG3/8
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB63X25S
The AirTAC SAILB63X25-S is a double-acting ISO 15552 profile cylinder equipped with a built-in mechanical lock housed in the back cover. Driven by a 20mm carbon steel rod, it generates 1559N of push force at 0.5MPa. The lock is spring-applied and air-released, meaning it automatically engages to hold the rod securely at the retracted stroke end whenever release air pressure is removed, ensuring loads remain safely parked without relying on live system pressure.
This unit includes a magnetic piston (-S) for precise end-of-stroke detection with CMSE reed or DMSE electronic sensors. Because the locker mechanism occupies end-cover space, the variable air cushion at the locker end is 21mm, which is shorter than the 30mm cushion found on the free end. The lock functions purely as a static holding device after the piston stops, rather than a dynamic brake for a moving rod.
Airtac SAILB Rear Lock Cylinder SAILB63X25S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB63X25S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø63 mm |
| Stroke | 25 mm |
| Acting type | Double acting, with lock |
| Port size | G3/8 |
| Rod thread | M16×1.5 |
| 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 (30 mm free end / 21 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 (Ø63mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 1559 N | 1402 N |
| 0.7 MPa | 2182 N | — |
| Max (@1.0 MPa) | 318 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 SAILB63X25S Is Used
Vertical Retract Hold
Secures elevated loads in the retracted position during a power loss, preventing gravity-driven drops.
Safety Gate Hold
Locks a safety gate firmly in the open or closed retracted terminal position until air is supplied to release.
Clamp and Park
Holds a workpiece securely at the retracted stroke end after the machining cycle finishes and pressure stops.
Is the Airtac SAILB Rear Lock Cylinder SAILB63X25S the Right Lock Cylinder?
Choose this 63mm bore if your application requires around 1559N push force at 0.5MPa; step down to a 50mm bore for 982N, or up to an 80mm bore for 2513N. Select this SAILB configuration when the load must be secured in the retracted position, and choose a SAILF variant instead if you need holding force at the extended end. If your workflow demands clamping at an arbitrary mid-stroke point rather than a stroke-end hold, the BSAI clamp-lock cylinder is the correct alternative.
For safe operation, avoid using fast-exhaust valves, as back-pressure on the locker side can unintentionally release the lock; an independent-exhaust solenoid valve is required. The PT ported design uses standard ISO 15552 mounting interfaces like FA, FB, and TC. If human safety depends on the load staying retracted, always add an independent safety measure alongside the lock. Replacement requires matching the 25mm stroke, back locker position, 3/8 port, and -S magnet.
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 SAILB63X25S FAQ
At 0.5MPa, this 63mm bore cylinder provides 1559N of push force and 1402N of pull force. At 0.7MPa, the push force increases to 2182N.
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 piston stops and unlocks via automatic air supply or a manual release lever.
Related AirTAC Lock & Standard Cylinders
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