Airtac SAILB Rear Lock Cylinder SAILB50X350S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB50X350S is a genuine double-acting ISO 15552 profile cylinder with a Ø50mm bore, 350mm 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.
- BoreØ50 mm
- Stroke350 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB50X350S
The AirTAC SAILB50X350-S is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. Because the lock is spring-applied and air-released, cutting the release air drives a lock pin into the 20mm carbon steel rod, securely holding the load at the retracted stroke end without requiring live pressure. You can unlock it automatically by supplying air to the release port or by using the manual release lever. This 50mm bore generates 982N of thrust at 0.5MPa, making it highly effective for vertical power-failure safety holds.
The integrated lock engages only after the piston reaches the stroke terminal on the locker side, functioning as a static holding device rather than a dynamic brake for a moving rod. For mid-stroke clamping requirements, the BSAI clamp-lock series is the correct alternative. The variable air cushion at the locker end is 20mm, intentionally shorter than the 30mm cushion at the free end to accommodate the lock mechanism. Furthermore, this variant includes a magnet for seamless integration with CMSE reed and DMSE electronic solid-state sensors.
Airtac SAILB Rear Lock Cylinder SAILB50X350S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB50X350S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø50 mm |
| Stroke | 350 mm |
| Acting type | Double acting, with lock |
| Port size | G1/4 |
| 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 / 20 mm lock end) |
| Max stroke | Up to 1200 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 (Ø50mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 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 SAILB50X350S Is Used
Vertical Load Safety
Secures lifted loads in the retracted position instantly upon power or air loss, preventing sudden drops.
Power Failure Hold
Maintains position during unexpected outages using the spring-applied lock, requiring no continuous air pressure.
End-of-Stroke Clamp
Holds a workpiece firmly at the retracted stroke terminal during machining or processing operations.
Is the Airtac SAILB Rear Lock Cylinder SAILB50X350S the Right Lock Cylinder?
Choose this 50mm bore when an application requires 982N of push force at 0.5MPa; if your load demands less force, stepping down to a 40mm bore yields 628N, while upgrading to a 63mm bore provides 1559N. Select this SAILB configuration specifically when the load must be secured in the retracted position, whereas the SAILF variant is needed to hold the extended stroke end. Since the stroke is 350mm, incorporating an external guide mechanism is recommended to manage side loads and prevent rod binding.
Remember that the lock provides a static hold exclusively at the stroke end, not at arbitrary intermediate positions. Valve selection is critical: never use a fast-exhaust valve with this cylinder, as back-pressure on the locker side can inadvertently release the lock; always utilize an independent-exhaust solenoid valve. If human safety relies on the load remaining elevated, implement an additional independent safety measure. For replacements, verify the 50mm bore, 350mm stroke, back locker position, PT threaded ports, and the -S magnet option.
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 SAILB50X350S FAQ
At an operating pressure of 0.5MPa, this 50mm bore cylinder generates 982N of push force and 825N of pull force. At the maximum pressure of 1.0MPa, it can deliver up to 200kgf.
The lock is spring-applied and air-released, meaning it engages automatically when the piston reaches the retracted stroke end or upon air loss. It is a static hold, not a dynamic brake, and can be released automatically via air supply or manually via a lever.
Related AirTAC Lock & Standard Cylinders
Request a Quote for Airtac SAILB Rear Lock Cylinder SAILB50X350S
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.