Airtac SAILB Rear Lock Cylinder SAILB63X50
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB63X50 is a genuine double-acting ISO 15552 profile cylinder with a Ø63mm bore, 50mm 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
- Stroke50 mm
- Port sizeG3/8
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB63X50
The AirTAC SAILB63X50 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the back cover. This mechanism securely holds the rod at the retracted stroke end, ensuring loads remain safely in place without requiring continuous live air pressure. It delivers a robust 1559N of push force at 0.5MPa, making it well-suited for mid-range power-loss safety applications.
Unlike a plain SAI cylinder, this model integrates a static holding lock that engages only after the piston stops at the terminal position. To accommodate the locking hardware, the variable air cushion at the locker end is shorter, measuring 21mm compared to the 30mm cushion on the free end. The standard carbon steel rod provides durability, and the lock can be released automatically via air or manually via a lever.
Airtac SAILB Rear Lock Cylinder SAILB63X50 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB63X50 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø63 mm |
| Stroke | 50 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 SAILB63X50 Is Used
Vertical Retract Safety
Holds a lifted load securely in the retracted position during a sudden air pressure loss, preventing accidental descent.
End-of-Stroke Clamp
Maintains positive mechanical clamping force on a workpiece at the retracted stroke end without consuming continuous air.
Gate Safety Hold
Keeps safety gates or heavy doors firmly closed in the retracted state until the air-release port is actively powered.
Is the Airtac SAILB Rear Lock Cylinder SAILB63X50 the Right Lock Cylinder?
Choose this 63mm bore when you need the 1559N push force at 0.5MPa, stepping up from a 50mm bore that provides 982N, or down from an 80mm bore offering 2513N. Select the SAILB configuration specifically when the load must be held in the retracted (rod-in) position; if your application requires holding at the extended end, the SAILF variant is the correct choice. For applications demanding a clamp at an arbitrary mid-stroke point, the BSAI clamp-lock cylinder should be used instead.
Remember that this lock is a static holding device, not a dynamic brake for a moving rod. Valve selection is critical: avoid fast-exhaust valves and use an independent-exhaust solenoid valve, as back-pressure on the locker side can unintentionally release the lock. If human safety depends on the load staying retracted, always add an independent safety measure. When replacing, verify the 50mm stroke, PT 3/8 port, and your required mounting style from the ISO 15552 options.
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 SAILB63X50 FAQ
At 0.5MPa operating pressure, 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 only at the retracted stroke end. It engages statically after the cylinder stops and is released automatically by supplying air to the release port or manually via a lever.
Related AirTAC Lock & Standard Cylinders
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