Airtac SAILB Rear Lock Cylinder SAILB40X50S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB40X50S is a genuine double-acting ISO 15552 profile cylinder with a Ø40mm 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.
- BoreØ40 mm
- Stroke50 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM12×1.25
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB40X50S
The AirTAC SAILB40X50-S is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. It delivers 628N of push force and 528N of pull force at 0.5MPa. The lock is spring-applied and air-released, meaning it engages automatically when the piston reaches the retracted stroke end. This ensures the load stays firmly held without requiring live air pressure.
Unlike a standard SAI cylinder, this model provides true power-loss safety. The variable air cushion at the locker end is 20mm, intentionally shorter than the 27mm cushion on the free end, to accommodate the locking mechanism. For position sensing, the integrated magnet works seamlessly with AirTAC CMSE reed and DMSE electronic solid-state switches.
Airtac SAILB Rear Lock Cylinder SAILB40X50S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB40X50S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø40 mm |
| Stroke | 50 mm |
| Acting type | Double acting, with lock |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| 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 (27 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 (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 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 SAILB40X50S Is Used
Vertical Load Holding
Prevents gravity-loaded vertical assemblies from dropping when air pressure is lost, securing the retracted position.
Power-Out Safety Gate
Holds a safety barrier closed at the rod-in stroke end during a sudden power or air supply failure.
End-of-Stroke Clamping
Maintains a static clamping force on a workpiece at the retracted terminal without consuming continuous air.
Is the Airtac SAILB Rear Lock Cylinder SAILB40X50S the Right Lock Cylinder?
Choose this 40mm bore if your application requires 628N push force at 0.5MPa and a fail-safe hold at the rod-in position. If you need higher thrust, the 50mm bore offers 982N at 0.5MPa. Select SAILB to hold the retracted end, or SAILF if you need the rod-out position secured. If your process requires clamping at an arbitrary mid-stroke point rather than the stroke end, use the BSAI clamp-lock cylinder instead.
This lock is a static holding device that engages after the cylinder stops, not a dynamic brake for moving rods. Valve selection is critical: never use a fast-exhaust valve, as back-pressure on the locker side can accidentally release the lock; always use an independent-exhaust solenoid valve. For human-safety-critical loads, add an independent mechanical safety measure. Replacement requires matching the 40mm bore, 50mm stroke, PT tapered ports, back locker position, 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 SAILB40X50S FAQ
At 0.5MPa, it provides 628N of push force and 528N of pull force. At 0.7MPa, the push force increases to 879N, and at 0.9MPa it reaches 1130N.
The lock is spring-applied and air-released, engaging only when the piston reaches the retracted stroke end in the back cover. It provides a static hold, not a dynamic brake. You can unlock it automatically by supplying air to the release port or by using the manual release lever.
Related AirTAC Lock & Standard Cylinders
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