Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X125S
The AirTAC Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X125S is a genuine double-acting ISO 15552 profile cylinder with a Ø40mm bore, 125mm 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
- Stroke125 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 SAILF40X125S
The AirTAC SAILF40X125-S is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the front cover. Because the lock sits in the front end, it engages when the piston reaches the extended stroke end, securely holding the rod-out position. A spring applies the locking pin automatically, while releasing the lock requires supply air to the release port or using the manual override lever. This power-failure safety mechanism ensures your vertical or extended loads remain exactly where they stopped.
Within the 40mm bore class, this unit generates 879N of push force and 528N of pull force at 0.7 MPa. The extruded aluminum barrel includes dual sensor grooves, and the -S option provides a built-in magnet compatible with AirTAC CMSE reed and DMSE solid-state sensors. The variable air cushion at the locker end is notably shorter, measuring 20mm compared to the 27mm cushion on the free end, a specific design choice to physically accommodate the locking hardware.
Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X125S Technical Specifications
| Model | Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X125S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø40 mm |
| Stroke | 125 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 SAILF40X125S Is Used
Vertical Lift Hold
Secures an extended vertical lift safely in place during a power loss or air pressure drop, preventing gravity-driven falls.
Gate Stop Position
Locks a diverter gate or conveyor flow barrier in the fully extended open path, ensuring it remains rigid even if supply pressure fluctuates.
Clamp and Hold
Maintains outward clamping pressure on a machined part at the stroke end without consuming continuous live air pressure.
Is the Airtac SAILF Front Locking Pneumatic Cylinder SAILF40X125S the Right Lock Cylinder?
Choose this 40mm bore when your application requires up to 879N of thrust at 0.7 MPa and you need to secure a load at the rod-out stroke end. If your project demands higher force, stepping up to the 50mm bore yields 1374N of push force at the same pressure. Select the SAILF configuration specifically when the extended position is the critical safety state; conversely, choose SAILB if the retracted rod-in position must be held. If your workflow requires locking at an arbitrary mid-stroke point rather than the stroke terminal, the BSAI clamp-lock cylinder is the correct alternative.
Remember that the SAIL lock is a static holding device that engages after the cylinder stops, not a dynamic brake for a moving rod. Avoid using fast-exhaust valves with this lock cylinder; instead, specify an independent-exhaust solenoid valve, as back-pressure on the locker side can unintentionally lift the lock. For any application where human safety depends on the load staying extended, always add an independent secondary safety measure. Replacement matches require the exact 125mm stroke, front locker position, PT port threads, 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 SAILF40X125S FAQ
At a 0.7 MPa operating pressure, the 40mm bore generates 879N of push force and 528N of pull force. The maximum thrust is 128 kgf at 1.0 MPa.
The lock is spring-applied and air-released, engaging only when the piston reaches the extended stroke end. It provides a static hold after the rod stops, not a mid-stroke clamp. Unlocking is achieved automatically by supplying air to the release port or manually via the override lever.
Related AirTAC Lock & Standard Cylinders
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