Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X50
The AirTAC Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X50 is a genuine double-acting ISO 15552 profile cylinder with a Ø125mm bore, 50mm 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
- Stroke50 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 SAILF125X50
The AirTAC SAILF125X50 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the front cover. This locking mechanism engages automatically to hold the rod securely at the extended stroke end whenever the release air is cut, maintaining the load position without requiring live pressure. Equipped with a carbon steel rod and a 1/2 PT port, it generates 8590N of push force and 5734N of pull force at 0.7 MPa, making it well-suited for heavy-duty positioning tasks.
Because the lock is integrated into the front end cap, the variable air cushion on that locker side is notably shorter, measuring 24mm compared to the 40mm cushion on the free end. The cylinder operates at speeds from 30 to 500 mm/s and accommodates AirTAC CMSE reed and DMSE electronic sensors via its dual-side barrel grooves. For safe operation, avoid using fast-exhaust valves, as back-pressure on the locker side can inadvertently release the lock.
Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X50 Technical Specifications
| Model | Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X50 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø125 mm |
| Stroke | 50 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 SAILF125X50 Is Used
Extended Load Holding
Secures heavy vertical loads in the fully extended position during power loss, preventing sudden drops on lifting mechanisms.
End-of-Stroke Clamp
Maintains rigid clamping pressure at the rod-out stroke end without consuming continuous compressed air, saving energy.
Gate Safety Interlock
Keeps heavy safety gates and machine guards locked open at the extended terminal until an intentional air release signal is sent.
Is the Airtac SAILF Front Locking Pneumatic Cylinder SAILF125X50 the Right Lock Cylinder?
Select this 125mm bore model when an application requires holding a heavy load at the fully extended position during a power loss or emergency stop. If your thrust requirements are lower, stepping down to an 80mm bore yields 3518N of push force at 0.7 MPa, whereas moving up to a 160mm bore provides 14074N. Choose the SAILF configuration specifically when the extended rod-out position must be secured; if the retracted position needs holding, the SAILB variant is required instead.
Remember that this SAIL lock is a static holding device that engages only after the cylinder has stopped at the stroke terminal, not a dynamic brake for a moving rod, nor a mid-stroke clamp like the BSAI series. Always use an independent-exhaust solenoid valve to prevent accidental lock release from back-pressure, and add an independent safety measure if human safety depends on the load staying elevated. For replacements, verify the 50mm stroke, front locker position, 1/2 PT port, and your required mounting style from the Basic, FA, FB, CA, CB, CR, LB, TC, FTC, TCM1, or TCM2 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 SAILF125X50 FAQ
At an operating pressure of 0.7 MPa, this 125mm bore cylinder provides 8590N of push force and 5734N of pull force. It can deliver up to 11045N of push force at 0.9 MPa.
The lock is spring-applied and air-released, engaging only when the piston reaches the extended stroke end in the front cover. It provides a static hold after the rod stops, not a mid-stroke clamp or dynamic brake. Unlocking occurs automatically by supplying release air or manually via the release lever.
Related AirTAC Lock & Standard Cylinders
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