Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X250
The AirTAC Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X250 is a genuine double-acting ISO 15552 profile cylinder with a Ø125mm 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.
- BoreØ125 mm
- Stroke250 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 SAILF125X250
The AirTAC SAILF125X250 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the front cover. This mechanism engages automatically when the piston reaches the extended stroke end, securely holding the load without requiring live air pressure. With a robust 125mm bore, it generates 8590N of push force and 5734N of pull force at 0.7 MPa, making it highly capable for heavy-duty positioning tasks.
Unlike a standard SAI cylinder, this model safely secures the rod-out position during power loss. The lock is a static holding device, not a dynamic brake for a moving rod. To ensure proper function, the variable air cushion at the locker end is 24mm, intentionally shorter than the 40mm cushion on the free end. The carbon steel rod and extruded aluminum barrel are designed for 30-500 mm/s operating speeds.
Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X250 Technical Specifications
| Model | Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X250 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø125 mm |
| Stroke | 250 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 SAILF125X250 Is Used
Vertical Lift Safety
Holds a raised platform securely at the extended stroke end during an unexpected air pressure loss, preventing sudden drops.
Heavy Clamp Hold
Maintains maximum clamping force on large workpieces at the rod-out position without consuming continuous compressed air.
Gate Security
Locks heavy industrial gates or doors in the open position, requiring an intentional air release signal to unlock.
Is the Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X250 the Right Lock Cylinder?
Choose this 125mm bore cylinder when an application requires substantial holding force at the fully extended position; if your thrust requirements are lower, the 100mm bore offers 5497N push at 0.7 MPa. Select the SAILF configuration specifically when the load must be held at the rod-out end, whereas SAILB holds the retracted position. If your process requires clamping at an arbitrary mid-stroke point rather than the stroke terminal, the BSAI clamp-lock cylinder is the correct alternative.
For safe operation, never use a fast-exhaust valve with this lock cylinder; an independent-exhaust solenoid valve is mandatory because back-pressure on the locker side can unintentionally release the lock. Always confirm the exact lock holding force from the official datasheet, and if human safety depends on the load remaining extended, add an independent safety measure. When replacing this unit, match the 125mm bore, 250mm stroke, front locker position, PT port threads, and mounting style. Although this 250mm stroke is under the 300mm threshold, utilizing standard ISO 15552 mounting options like TC or FA ensures optimal side-load management.
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 SAILF125X250 FAQ
At 0.7 MPa, this 125mm bore cylinder provides 8590N of push force and 5734N of pull force. The maximum operating pressure is 1.0 MPa.
The lock is spring-applied and air-released, engaging statically when the piston reaches the extended stroke end. It unlocks automatically via air supply to the release port or manually via a lever. It does not clamp at mid-stroke.
Related AirTAC Lock & Standard Cylinders
Request a Quote for Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X250
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.