Airtac SAILB Rear Lock Cylinder SAILB50X900S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB50X900S is a genuine double-acting ISO 15552 profile cylinder with a Ø50mm bore, 900mm 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
- Stroke900 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB50X900S
The AirTAC SAILB50X900-S is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. Because it includes a magnet (-S), it supports AirTAC CMSE reed and DMSE electronic sensors for precise end-of-stroke detection. A spring-applied, air-released lock engages when the piston reaches the retracted stroke end, securely holding the load without requiring live pressure.
Delivering 982N of push force and 825N of pull force at 0.5 MPa, this 50mm bore unit uses a 1/4 PT port and a 20mm carbon steel rod. The variable air cushion at the locker end is 20mm, intentionally shorter than the 30mm cushion on the free end to accommodate the locking mechanism. This static lock engages only after the cylinder stops; it is not a dynamic brake for a moving rod.
Airtac SAILB Rear Lock Cylinder SAILB50X900S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB50X900S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø50 mm |
| Stroke | 900 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 SAILB50X900S Is Used
Vertical Lift Safety
Secures elevated platforms in the retracted position instantly upon air pressure loss, preventing uncontrolled drops.
Pallet Stopper Hold
Locks a pneumatic stopper blade in the retracted rod-in position to keep the conveyor lane clear without consuming air.
Machine Guard Hold
Maintains a safety guard open at the retracted stroke end during maintenance, ensuring it stays put if air supply is cut.
Is the Airtac SAILB Rear Lock Cylinder SAILB50X900S the Right Lock Cylinder?
Choose this 50mm bore when 825N of pull force at 0.5 MPa is sufficient for your load; stepping up to a 63mm bore provides 1402N if your application requires heavier retracted holding. Select the SAILB configuration when the load must be secured in the rod-in position, and select SAILF if it must be held at the extended stroke end. If your application requires locking at an arbitrary mid-stroke position rather than the stroke end, use the BSAI clamp-lock cylinder instead.
For this 900mm stroke, adding an external guide is recommended to prevent excessive side-load wear on the rod seals. The lock relies on an independent-exhaust solenoid valve; never use a fast-exhaust valve, as back-pressure on the locker side can unintentionally release the lock. For human-safety critical overhead loads, always add an independent mechanical safety measure. Replacement requires matching the 50mm bore, 900mm stroke, back locker position, PT ports, 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 SAILB50X900S FAQ
At 0.5 MPa, this 50mm bore cylinder provides 982N of push force and 825N of pull force. At 0.7 MPa, the push force increases to 1374N.
The spring-applied, air-released lock engages automatically when the piston reaches the retracted stroke end in the back cover. It provides a static hold only, not a mid-stroke clamp or dynamic brake. Unlocking requires supplying air to the release port or using the manual release lever.
Related AirTAC Lock & Standard Cylinders
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