Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X400
The AirTAC Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X400 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
- 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 SAILF125X400
The AirTAC SAILF125X400 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock built into the front cover. Because the lock resides in the front end, it engages only when the piston reaches the extended stroke end, securely holding the rod out without relying on live air pressure. In this bore size, the cylinder generates 6136N of push force and 5734N of pull force at 0.5 MPa, utilizing a 32mm carbon steel rod and a 1/2-inch PT port.
A critical mechanical detail is that the variable air cushion at the locker end measures 24mm, which is intentionally shorter than the 40mm cushion found at the free end. The lock itself is a static holding device that engages after the cylinder stops; it is not a dynamic brake for a moving rod. To maintain safe lock engagement, avoid using fast-exhaust valves, as back-pressure on the locker side can unintentionally release the lock.
Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X400 Technical Specifications
| Model | Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X400 |
|---|---|
| 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 SAILF125X400 Is Used
Vertical Lift Holding
Holds a raised load securely at the extended stroke end when air pressure drops, preventing sudden drops on lifting platforms.
Pallet Stop Gate
Maintains an extended stop gate position on a conveyor line during power loss, ensuring product queue control without live air.
Safety Guard Lock
Keeps a machine safety guard fully extended and locked open during maintenance until the release air is intentionally supplied.
Is the Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X400 the Right Lock Cylinder?
Choose this 125mm bore when an application requires holding a load at the fully extended stroke end during a power loss, stepping up from the 100mm bore which provides 3927N push at 0.5 MPa. If the mechanical hold must occur at the retracted position, select the SAILB variant instead. For applications needing to clamp and hold the rod at an arbitrary mid-stroke point rather than a stroke end, the AirTAC BSAI clamp-lock cylinder is the correct choice.
This 400mm stroke model falls within the 1500mm maximum standard stroke limit for this bore, but its extended length necessitates careful attention to side-load forces; utilizing external guide rails is recommended to prevent shaft binding. The lock provides a static stroke-end hold, not a dynamic brake, so safety-critical vertical lifts should always include an independent mechanical safety measure. Replacement or matching units must specify the 125mm bore, 400mm stroke, front locker position, 1/2-inch PT port, and the desired mounting style from the available ISO 15552 interface options.
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 SAILF125X400 FAQ
At a 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 releases automatically by supplying air to the release port or manually via the lever; it does not clamp at mid-stroke.
Related AirTAC Lock & Standard Cylinders
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