Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250S
The AirTAC Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250S is a genuine double-acting ISO 15552 profile cylinder with a Ø40mm bore, 250mm stroke and a built-in spring-applied, air-released mechanical lock in the front cover — it holds the load at the extended (rod-out) stroke end even when air is lost.
- BoreØ40 mm
- Stroke250 mm
- Port sizeG1/4
- Lock positionFront cover
- Rod threadM12×1.25
- UnlockAir + manual
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250S
The AirTAC SAILF40X250-S is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the front cover. Because this is a SAILF variant, the spring-applied, air-released lock engages when the piston reaches the extended stroke end, securely holding the rod-out position without requiring live air pressure. In the 40mm bore class, it generates 879N of push force and 528N of pull force at 0.7MPa. The standard carbon steel rod and integrated magnet allow seamless operation with AirTAC CMSE reed and DMSE electronic solid-state sensors.
This model features a PT tapered port thread and variable air cushions at both ends. Notably, the cushion at the locker end is shorter (20mm) compared to the free end cushion (27mm) to accommodate the locking hardware. The lock is a static holding device that engages after the cylinder stops; it is not a dynamic mid-stroke brake. For mid-stroke clamping, a BSAI clamp-lock cylinder is required instead.
Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250S Technical Specifications
| Model | Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø40 mm |
| Stroke | 250 mm |
| Acting type | Double acting, with lock |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| Lock type | Spring-applied, air-released (front 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 extended (rod-out) 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 front-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 SAILF Front Locking Pneumatic Cylinder SAILF40X250S Is Used
Vertical Lift Hold
Maintains an extended vertical load securely in the rod-out position during a sudden air pressure loss, preventing uncontrolled drops.
Flow Stop Gate
Keeps a conveyor diversion gate locked open at the stroke end without consuming continuous air supply, reducing energy use.
Safety Barrier
Holds a protective barrier extended in a guarded zone, requiring an intentional air-release signal to retract.
Is the Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250S the Right Lock Cylinder?
Select this 40mm bore cylinder when an application needs to hold a load securely at the extended rod-out position during a power or air loss event. If your application requires a higher load capacity, stepping up to the 50mm bore provides 1374N of push force at 0.7MPa. Choose SAILF for front-cover extended-end holding, or SAILB if the retracted rod-in hold is needed. Remember that this lock holds only at the stroke terminal; if you need locking at an arbitrary mid-stroke position, select the BSAI series instead.
For safe operation, avoid using fast-exhaust valves, as back-pressure on the locker side can unintentionally release the lock; an independent-exhaust solenoid valve is required. Because this unit has a 250mm stroke, using an external guide is recommended to prevent excessive side-load wear on the cylinder seals. To replace this unit, match the 40mm bore, 250mm stroke, front locker position, PT port, and the -S magnet option.
Quick checklist
- ✓ Hold needed at the extended (rod-out) end?
- ✓ Or lock anywhere → use BSAI
- ✓ Independent-exhaust valve fitted
- ✓ Port/thread type (PT/G)
- ✓ Extra safety measure for people
Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250S FAQ
At 0.7MPa operating pressure, this 40mm bore cylinder provides 879N of push force and 528N of pull force. The maximum operating pressure is 1.0MPa.
The lock is spring-applied and air-released, engaging statically at the extended stroke end to hold the load without live pressure. It unlocks automatically via air supply or manually via a lever, but it does not clamp at arbitrary mid-stroke positions.
Related AirTAC Lock & Standard Cylinders
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