Airtac SAILB Rear Lock Cylinder SAILB125X350S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB125X350S is a genuine double-acting ISO 15552 profile cylinder with a Ø125mm bore, 350mm 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
- Stroke350 mm
- Port sizeG1/2
- Lock positionBack cover
- Rod threadM27×2
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB125X350S
The AirTAC SAILB125X350-S is a double-acting ISO 15552 profile cylinder equipped with a spring-applied, air-released mechanical lock housed in the back cover. This lock engages automatically to hold the rod securely at the retracted stroke end whenever release air pressure is removed, ensuring static load retention without relying on live air. Featuring a 125mm bore, it provides 6136N of push force and 5734N of pull force at 0.5MPa, making it ideal for heavy-duty positioning. The integrated -S magnet enables position detection with CMSE reed and DMSE solid-state sensors.
Because the lock occupies the back cover, the variable air cushion on that locker end is shorter, measuring 24mm compared to 40mm on the free end. The cylinder operates at speeds of 30-500mm/s and uses a PT tapered port. The lock is a static holding device, not a dynamic brake, and requires an independent-exhaust solenoid valve to prevent back-pressure from releasing the lock.
Airtac SAILB Rear Lock Cylinder SAILB125X350S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB125X350S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø125 mm |
| Stroke | 350 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 SAILB125X350S Is Used
Vertical Power-Off Hold
Secures heavy lifted platforms in the retracted position instantly upon air pressure loss, preventing uncontrolled drops.
Static Clamp Retention
Maintains a high-force clamping state at the rod-in stroke end without consuming continuous compressed air.
Safety Gate Interlock
Holds safety barriers and gates firmly closed at the retracted terminal until an explicit air release signal is sent.
Is the Airtac SAILB Rear Lock Cylinder SAILB125X350S the Right Lock Cylinder?
Select this 125mm bore model when an application demands high force (6136N push at 0.5MPa) alongside guaranteed load holding at the retracted position. If your force requirements are lower, stepping down to the 100mm bore yields 3927N push, while moving up to the 160mm bore provides 10053N. Choose SAILB specifically when the load must be secured in the rod-in retracted state; for holding at the extended rod-out state, the SAILF variant is required. If your process requires locking at an arbitrary mid-stroke point rather than the stroke end, select the BSAI clamp-lock cylinder instead.
For safe operation, never use a fast-exhaust valve with this cylinder, as back-pressure on the locker side can unintentionally lift the lock. The lock holds statically only after the piston has stopped at the stroke end. With a 350mm stroke, ensure external guide rails are used to manage side loads and prevent rod binding. Replacement units must match the 125mm bore, 350mm stroke, back locker position, PT port thread, and -S magnet configuration.
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 SAILB125X350S FAQ
At 0.5MPa operating pressure, this 125mm bore cylinder generates 6136N of push force and 5734N of pull force. At the maximum 1.0MPa pressure, it delivers a maximum push force equivalent to 1251kgf.
The lock is spring-applied and air-released, located in the back cover to hold the rod exclusively at the retracted stroke end. It engages statically after the cylinder stops and unlocks automatically via air supply or a manual release lever. It does not clamp at mid-stroke, and an independent-exhaust solenoid valve must be used to prevent back-pressure from releasing the lock.
Related AirTAC Lock & Standard Cylinders
Request a Quote for Airtac SAILB Rear Lock Cylinder SAILB125X350S
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.