Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X400S
The AirTAC Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X400S is a genuine double-acting ISO 15552 profile cylinder with a Ø125mm bore, 400mm 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.
- BoreØ125 mm
- Stroke400 mm
- Port sizeG1/2
- Lock positionFront cover
- Rod threadM27×2
- UnlockAir + manual
About the Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X400S
The AirTAC SAILF125X400-S is a double-acting ISO 15552 profile cylinder equipped with a mechanical lock in the front cover. Because it is an F-series unit, the spring-applied, air-released lock engages when the piston reaches the extended stroke end, securely holding the rod-out position. In the 125mm bore class, it generates 6136N of push force and 5734N of pull force at 0.5 MPa, making it suited for heavy vertical lifting tasks. The integrated -S magnet enables position sensing with CMSE reed or DMSE electronic switches.
This unit features a carbon steel rod and PT tapered port threads. A critical design detail is that the variable air cushion at the locker end is shorter (24mm) than the free-end cushion (40mm). The lock itself provides static holding without live air pressure, whereas the cushion only decelerates the piston near stroke termination. You can release the lock automatically by supplying air to the release port or by using the manual release lever.
Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X400S Technical Specifications
| Model | Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X400S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø125 mm |
| Stroke | 400 mm |
| Acting type | Double acting, with lock |
| Port size | G1/2 |
| Rod thread | M27×2 |
| 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 – 500 mm/s |
| Cushion | Adjustable (40 mm free end / 24 mm lock end) |
| Max stroke | Up to 1500 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 (Ø125mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 6136 N | 5734 N |
| 0.7 MPa | 8590 N | — |
| Max (@1.0 MPa) | 1251 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 SAILF125X400S Is Used
Extended Lift Holding
Secures vertical lifts in the rod-out position during power loss, preventing heavy loads from dropping when air pressure is cut.
Pallet Stop Gate
Holds a raised pallet stop gate open at the extended stroke end without consuming continuous live air pressure.
Safety Guard Positioning
Maintains a safety guard in the extended locked position, requiring an air signal to release and retract safely.
Is the Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X400S the Right Lock Cylinder?
Choose this 125mm bore when a 100mm bore (providing 3927N push at 0.5 MPa) is insufficient, or step down to an 80mm bore (2513N push) for lighter loads. Select the SAILF configuration when the load must be secured at the extended rod-out position; if your application requires holding at the retracted position, a SAILB variant is needed instead. For applications demanding mid-stroke clamping rather than end-of-stroke holding, the BSAI clamp-lock cylinder is the correct choice.
The lock is a static holding device that engages after the cylinder stops, not a dynamic brake for a moving rod. Never use a fast-exhaust valve with this cylinder; back-pressure on the locker side can unintentionally release the lock, so an independent-exhaust solenoid valve is required. If human safety depends on the load remaining extended, add an independent safety measure. With a 400mm stroke, use external guide rails to prevent side-load damage to the carbon steel rod. Replacement parts must match the 125mm bore, 400mm stroke, front locker position, PT threads, and -S magnet.
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 SAILF125X400S FAQ
At 0.5 MPa operating pressure, this 125mm bore cylinder provides 6136N of push force and 5734N of pull force. At 0.7 MPa, the push force increases to 8590N.
The lock is spring-applied and air-released, engaging statically only when the piston reaches the extended stroke end. It holds the load without live pressure and is released automatically via air supply or manually via a lever; it does not clamp at mid-stroke.
Related AirTAC Lock & Standard Cylinders
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