Airtac SAILB Rear Lock Cylinder SAILB63X300S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB63X300S is a genuine double-acting ISO 15552 profile cylinder with a Ø63mm bore, 300mm 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
- Stroke300 mm
- Port sizeG3/8
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB63X300S
The AirTAC SAILB63X300-S is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. Because it is a back-lock variant, a spring drives a lock pin into the carbon steel rod when the piston reaches the retracted stroke end, ensuring the load is held securely without live air pressure. In the 63mm bore class, it generates 1559N of push thrust and 1402N of pull thrust at 0.5MPa, making it well-suited for medium-force holding tasks.
This model includes the -S magnet option for position sensing with AirTAC CMSE reed and DMSE electronic switches. To unlock the rod, you supply air to the release port for automatic retraction or use the manual release lever. The variable air cushion at the locker end is 21mm, intentionally shorter than the 30mm cushion at the free end to accommodate the locking mechanism. Remember that the lock is a static holding device that engages after the cylinder stops; it is not a dynamic brake for a moving rod.
Airtac SAILB Rear Lock Cylinder SAILB63X300S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB63X300S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø63 mm |
| Stroke | 300 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 SAILB63X300S Is Used
Vertical Power-Off Hold
Secures lifted loads in the retracted position instantly when air pressure drops, preventing sudden drops on packaging and material handling lines.
Conveyor Arrest
Holds a gate or stopper cylinder rod firmly in the retracted end state during conveyor halts or emergency stops.
Machine Safety Guard
Locks a safety guard in the retracted open position without consuming continuous air, keeping the guard secure until the release port is pressurized.
Is the Airtac SAILB Rear Lock Cylinder SAILB63X300S the Right Lock Cylinder?
Select this 63mm bore model when your application requires up to 1559N of force at 0.5MPa and a fail-safe hold at the retracted position. If you need less force, the 50mm bore offers 982N of push thrust at 0.5MPa; if your load demands more, stepping up to the 80mm bore provides 2513N. Choose this SAILB configuration specifically when the load must be secured in the rod-in position, whereas a SAILF variant would hold the extended position.
If your machinery requires locking at an arbitrary mid-stroke point rather than a stroke end, the AirTAC BSAI clamp-lock cylinder is the correct choice instead. For the SAILB63X300-S, ensure you use an independent-exhaust solenoid valve, as fast-exhaust valves can cause back-pressure on the locker side and inadvertently release the lock. At 300mm of stroke, add an external guide to support side loads and prevent rod binding. Always add an independent mechanical safety measure if human safety depends on the load staying up. Replacement requires matching the 63mm bore, 300mm stroke, back locker position, PT tapered ports, and the -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 SAILB63X300S FAQ
At 0.5MPa, the 63mm bore provides 1559N of push thrust and 1402N of pull thrust. At 0.7MPa, the push force increases to 2182N.
The lock is spring-applied and air-released. It engages statically at the retracted stroke end to hold the load without live pressure. To unlock, supply air to the release port or use the manual release lever.
Related AirTAC Lock & Standard Cylinders
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