Airtac SAILB Rear Lock Cylinder SAILB125X1000
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB125X1000 is a genuine double-acting ISO 15552 profile cylinder with a Ø125mm bore, 1000mm 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
- Stroke1000 mm
- Port sizeG1/2
- Lock positionBack cover
- Rod threadM27×2
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB125X1000
The AirTAC SAILB125X1000 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the back cover. This lock engages automatically when the piston reaches the retracted stroke end, ensuring your load is held securely without requiring continuous live air pressure. You can release the lock pneumatically via the dedicated air port or use the manual release lever for maintenance. Delivering a push force of 6136N at 0.5MPa, this 125mm bore unit is built for heavy-duty holding tasks.
This model features a carbon steel rod and PT tapered port threads. The variable air cushion at the locker end is 24mm, deliberately shorter than the 40mm cushion at the free end to accommodate the locking mechanism. For position sensing, the extruded aluminum barrel includes sensor grooves on both sides compatible with AirTAC CMSE reed and DMSE electronic solid-state switches, though this specific SKU is supplied without a magnet. Note that this 1000mm stroke is a non-standard length for this bore size.
Airtac SAILB Rear Lock Cylinder SAILB125X1000 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB125X1000 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø125 mm |
| Stroke | 1000 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 SAILB125X1000 Is Used
Vertical Lift Safety
Holds heavy vertical loads securely at the retracted stroke end during a power loss, preventing gravity-driven falls on lifting machinery.
End-Stroke Clamping
Maintains solid clamping pressure on large workpieces at the fully retracted position without consuming continuous compressed air.
Gate and Door Hold
Secures heavy industrial gates or warehouse doors in the closed position, resisting wind or mechanical push-back until unlocked.
Is the Airtac SAILB Rear Lock Cylinder SAILB125X1000 the Right Lock Cylinder?
Choose this SAILB model when you specifically need the load held at the fully retracted rod-in position. If your application requires holding the load at the extended rod-out position, select the SAILF variant instead. For applications requiring mid-stroke clamping at arbitrary positions, the BSAI clamp-lock cylinder is the correct choice, as the SAIL lock only engages at the stroke terminal. If you need slightly less force, the 80mm bore offers 2513N at 0.5MPa; for higher force, the 160mm bore provides 10053N at 0.5MPa.
Because this is a 1000mm stroke, it exceeds the 1500mm maximum standard stroke for the 125mm bore, classifying it as a non-standard length. At this extended stroke, side-load sensitivity is high, so proper guide bushings and external load supports are strongly recommended to prevent rod binding. Remember that the lock is a static holding device, not a dynamic brake. Valve selection is critical: never use a fast-exhaust valve, and always use an independent-exhaust solenoid valve, as back-pressure on the locker side can unintentionally release the lock. For human-safety critical lifting applications, always add an independent mechanical safety measure.
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 SAILB125X1000 FAQ
The 125mm bore provides a push force of 6136N and a pull force of 5734N at 0.5MPa. At 0.7MPa, the push force increases to 8590N. The maximum operating pressure is 1.0MPa.
The lock is spring-applied and air-released, located in the back cover. It engages only after the piston stops at the retracted stroke end, holding the load statically without live pressure. It is not a mid-stroke clamp or dynamic brake. To unlock, you supply release air or use the manual lever. Always use an independent-exhaust solenoid valve, as back-pressure can release the lock.
Related AirTAC Lock & Standard Cylinders
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