Airtac SAILB Rear Lock Cylinder SAILB125X100S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB125X100S is a genuine double-acting ISO 15552 profile cylinder with a Ø125mm bore, 100mm stroke and a built-in spring-applied, air-released mechanical lock in the back cover — it holds the load at the retracted (rod-in) stroke end even when air is lost.
- BoreØ125 mm
- Stroke100 mm
- Port sizeG1/2
- Lock positionBack cover
- Rod threadM27×2
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB125X100S
The AirTAC SAILB125X100-S is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. Because this is a SAILB configuration, the spring-applied, air-released lock engages automatically when the piston reaches the retracted stroke end. It provides a robust holding force for heavy loads, delivering 6136N of push thrust and 5734N of pull thrust at 0.5 MPa. The carbon steel rod and integrated magnet for CMSE and DMSE sensors make it highly versatile for demanding automation setups.
Unlike a standard SAI cylinder, this unit retains the load entirely without live pressure. The lock is a static holding device, not a dynamic brake for a moving rod. To accommodate the locking hardware, the variable air cushion at the locker end is 24 mm, which is shorter than the 40 mm cushion found on the non-locking front end. Always confirm the specific lock holding capacity from the official datasheet for your exact load requirements.
Airtac SAILB Rear Lock Cylinder SAILB125X100S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB125X100S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø125 mm |
| Stroke | 100 mm |
| Acting type | Double acting, with lock |
| Port size | G1/2 |
| Rod thread | M27×2 |
| Lock type | Spring-applied, air-released (back 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 retracted (rod-in) 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 back-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 SAILB Rear Lock Cylinder SAILB125X100S Is Used
Vertical Lift Holding
Prevents heavy elevators from dropping under power loss by locking the rod securely in the retracted end position without requiring continuous air pressure.
Clamp and Secure
Maintains high-force clamping pressure on large metal fabrications at the end of the stroke, ensuring parts remain fixed during machining processes.
Safety Gate Locking
Keeps heavy industrial safety gates tightly closed and locked in the retracted position until the air-release signal is actively triggered.
Is the Airtac SAILB Rear Lock Cylinder SAILB125X100S the Right Lock Cylinder?
Select this 125 mm bore when a 100 mm bore maxing out at 3927N of push force is insufficient, but you want to avoid stepping up to a 160 mm bore that generates 10053N. Choose the SAILB variant specifically when the load must be secured in the retracted position; select SAILF instead if the extended position must be held. If your application requires clamping at an arbitrary mid-stroke point rather than a stroke-end hold, the BSAI clamp-lock cylinder is the correct choice.
For safe operation, never use a fast-exhaust valve with this cylinder, as back-pressure on the locker side can unintentionally release the lock; utilize an independent-exhaust solenoid valve instead. To unlock, supply air to the release port or use the manual override. If human safety relies on the load remaining suspended, implement an independent mechanical safety measure. When replacing this unit, match the 125 mm bore, 100 mm stroke, back locker position, 1/2 inch PT port, and the -S magnet option.
Quick checklist
- ✓ Hold needed at the retracted (rod-in) end?
- ✓ Or lock anywhere → use BSAI
- ✓ Independent-exhaust valve fitted
- ✓ Port/thread type (PT/G)
- ✓ Extra safety measure for people
Airtac SAILB Rear Lock Cylinder SAILB125X100S FAQ
At 0.5 MPa, this 125 mm bore cylinder provides 6136N of push thrust and 5734N of pull thrust. At 0.7 MPa, the push force increases to 8590N.
The spring-applied, air-released lock engages statically when the piston reaches the retracted stroke end in the back cover. It does not brake a moving rod or lock at mid-stroke. You can unlock it automatically by supplying release air or manually via the lever.
Related AirTAC Lock & Standard Cylinders
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