Airtac SAILB Rear Lock Cylinder SAILB80X250S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB80X250S is a genuine double-acting ISO 15552 profile cylinder with a Ø80mm bore, 250mm 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.
- BoreØ80 mm
- Stroke250 mm
- Port sizeG3/8
- Lock positionBack cover
- Rod threadM20×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB80X250S
The AirTAC SAILB80X250-S is a double-acting ISO 15552 profile cylinder featuring a built-in mechanical lock in the back cover. Because the lock is spring-applied and air-released, cutting the release air drives a lock pin into the rod, securely holding the load at the retracted stroke end without relying on continuous live pressure. You can unlock it automatically by supplying air to the release port or by using the manual release lever. With a 25mm carbon steel rod and a 3/8 PT port, it generates 2513N of push force at 0.5MPa.
This model includes a piston magnet for position sensing with CMSE reed and DMSE electronic switches. The variable air cushion at the locker end is 22.5mm, intentionally shorter than the 36mm cushion at the free end to accommodate the locking hardware. Remember that this is a static holding device that engages after the cylinder stops, not a dynamic brake for a moving rod.
Airtac SAILB Rear Lock Cylinder SAILB80X250S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB80X250S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø80 mm |
| Stroke | 250 mm |
| Acting type | Double acting, with lock |
| Port size | G3/8 |
| Rod thread | M20×1.5 |
| 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 – 800 mm/s |
| Cushion | Adjustable (36 mm free end / 22.5 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 (Ø80mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 2513 N | 2268 N |
| 0.7 MPa | 3519 N | — |
| Max (@1.0 MPa) | 513 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 SAILB80X250S Is Used
Vertical Load Hold on Power Loss
Secures a lifted vertical load in the retracted position instantly when air pressure drops, preventing crashes.
Clamp-and-Hold at End of Stroke
Maintains a firm mechanical grip on a clamped workpiece at the retracted terminal without consuming continuous air.
Safety Hold on Lifts and Gates
Keeps heavy safety gates and lifting mechanisms locked safely in the withdrawn state during maintenance.
Is the Airtac SAILB Rear Lock Cylinder SAILB80X250S the Right Lock Cylinder?
Choose this 80mm bore cylinder when an application requires 2513N of push force at 0.5MPa and a fail-safe hold at the retracted position. If you need less force, the 63mm bore offers 1559N at 0.5MPa; if your load demands more, stepping up to the 100mm bore provides 3927N at 0.5MPa. Select the SAILB configuration specifically when the rod must be secured in the retracted stroke-end position, whereas a SAILF variant would hold the extended rod out.
If your process requires clamping at an arbitrary mid-stroke point rather than at the end, use the BSAI clamp-lock cylinder instead. For the SAILB80X250-S, the lock holds statically at the stroke terminal, so never use a fast-exhaust valve, as back-pressure on the locker side can accidentally release the pin; always use an independent-exhaust solenoid valve. At a 250mm stroke, ensure you use appropriate mounting accessories and guide rails to prevent excessive side-load wear on the carbon steel rod. For human-safety critical loads, always add an independent mechanical safety measure alongside the lock.
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 SAILB80X250S FAQ
At 0.5MPa operating pressure, this 80mm bore cylinder provides 2513N of push force and 2268N of pull force. At 0.7MPa, the push force increases to 3518N.
The lock is spring-applied and air-released, meaning it engages automatically when the piston reaches the retracted stroke end and pressure is cut. It holds statically without live air. You can release it by supplying air to the release port or using the manual lever.
Related AirTAC Lock & Standard Cylinders
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