Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250
The AirTAC Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250 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 SAILF40X250
The AirTAC SAILF40X250 is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the front cover. Because it is a front-locker (SAILF), the spring-applied, air-released mechanism engages only when the piston reaches the extended stroke end, firmly holding the rod out without requiring continuous live air pressure. In this 40mm bore class, the cylinder generates 879N of push force at 0.7 MPa using a 16mm carbon steel rod.
The lock is a static holding device, not a dynamic brake for a moving rod. A key design trait is that the variable air cushion at the locker end is physically shorter (20mm) compared to the 27mm cushion on the free end. To release the load, you simply supply air to the release port for automatic unlocking or use the manual override lever.
Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250 Technical Specifications
| Model | Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250 |
|---|---|
| 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 SAILF40X250 Is Used
Vertical Lift Safety
Secures elevated loads at the fully extended stroke end, preventing sudden drops during a pneumatic power loss or emergency stop.
Pallet Stopper Arm
Extends out to halt heavy pallets on a packaging line and locks rigidly in place to withstand repeated impact without bouncing back.
Overhead Gate Hold
Holds an industrial gate or heavy access door firmly open at the end of the stroke, requiring a deliberate air signal to release and close.
Is the Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X250 the Right Lock Cylinder?
Choose this 40mm bore when your application requires 879N of push force at 0.7 MPa and a secure hold at the rod-out position. If your load demands less force, the neighboring 32mm bore is unavailable in the SAIL series, making 40mm the baseline minimum; if you need substantially more holding power, step up to the 50mm bore which provides 1374N of push at 0.7 MPa. Select SAILF for extended-end holding and SAILB for retracted-end holding. If your process requires locking at an arbitrary mid-stroke position rather than the stroke terminal, choose the BSAI clamp-lock cylinder instead.
For safe operation, never use a fast-exhaust valve with this lock cylinder; always use an independent-exhaust solenoid valve to prevent back-pressure on the locker side from accidentally releasing the lock. If human safety depends on the load remaining elevated, add an independent mechanical safety measure. This 250mm stroke model uses a 1/4 PT port, accepts standard ISO 15552 mountings (Basic, FA, FB, TC, etc.), and because the stroke is 250mm, ensure adequate guide rails to prevent excessive side-loading on the rod. Standard reed (CMSE) or solid-state (DMSE) sensors can be added if a magnet is specified.
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 SAILF40X250 FAQ
At 0.7 MPa operating pressure, the 40mm bore provides 879N of push force and 528N of pull force. It can deliver up to 1130N push at 0.9 MPa, with a maximum rated force of 128 kgf at 1.0 MPa.
The lock is spring-applied and air-released. It engages automatically when the rod reaches the extended stroke end, holding the load statically without live pressure. To unlock, supply air to the release port or use the manual release lever. It does not clamp at mid-stroke.
Related AirTAC Lock & Standard Cylinders
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