Airtac SAILB Rear Lock Cylinder SAILB63X250
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB63X250 is a genuine double-acting ISO 15552 profile cylinder with a Ø63mm bore, 250mm 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
- Stroke250 mm
- Port sizeG3/8
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB63X250
The AirTAC SAILB63X250 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the back cover. This mechanism secures the piston rod specifically at the retracted stroke end, maintaining the load position without requiring continuous live air pressure. With a 63mm bore, it generates 1559N of pull force at 0.5MPa, making it well-suited for moderate-load holding tasks.
The locking unit engages only after the cylinder comes to a complete stop, functioning as a static holding device rather than a dynamic brake for moving rods. To accommodate the internal lock hardware, the variable air cushion at the locker end is 21mm, intentionally shorter than the 30mm cushion on the free end. The standard carbon steel rod provides robust load transmission, and the extruded aluminum barrel is dimensionally interchangeable per ISO 15552 mounting interfaces.
Airtac SAILB Rear Lock Cylinder SAILB63X250 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB63X250 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø63 mm |
| Stroke | 250 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 SAILB63X250 Is Used
Vertical Lift Holding
Secures elevated loads in the retracted position during power loss, preventing sudden drops.
Conveyor Pneumatic Stop
Locks a pneumatic stop gate in the retracted terminal position without consuming continuous air.
Safety Gate Interlock
Maintains a safety barrier firmly closed at the stroke end until the release air is actively supplied.
Is the Airtac SAILB Rear Lock Cylinder SAILB63X250 the Right Lock Cylinder?
Select this 63mm bore model when your application requires 1559N of pull force at 0.5MPa or up to 2805N at 0.7MPa; if your load demands less force, stepping down to a 50mm bore yields 825N pull at 0.5MPa. Choose this SAILB configuration to hold the rod in the retracted position; if you need to secure the extended rod-out state, the SAILF variant is required instead. For applications demanding mid-stroke clamping at arbitrary positions, the BSAI clamp-lock cylinder is the correct alternative.
Because the lock is a static stroke-end device, never use a fast-exhaust valve with this cylinder, as back-pressure on the locker side can unintentionally release the lock—always use an independent-exhaust solenoid valve. If human safety relies on the load remaining retracted, add an independent mechanical safety measure. When replacing this unit, match the 63mm bore, 250mm stroke, back locker position, 3/8 PT port, and standard carbon steel rod. For this 250mm stroke, ensure external guides support side loads to prevent rod binding.
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 SAILB63X250 FAQ
At 0.5MPa, the 63mm bore provides 1559N of push force and 1402N of pull force. At 0.7MPa, the push force is 2182N, and the pull force is 1964N.
The lock is spring-applied and air-released, engaging only at the retracted stroke end in the back cover. It acts as a static hold after the rod stops, not a mid-stroke clamp or dynamic brake, and can be unlocked automatically via air or manually.
Related AirTAC Lock & Standard Cylinders
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