Airtac SAILB Rear Lock Cylinder SAILB80X250
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB80X250 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 SAILB80X250
The AirTAC SAILB80X250 is a double-acting ISO 15552 profile cylinder featuring a mechanical lock integrated into the back cover. Because the lock is spring-applied and air-released, it automatically engages to hold the rod at the retracted stroke end the moment release pressure is cut, securing the load without consuming live air. In this bore size, the cylinder generates 2513N of push force and 2268N of pull force at 0.5 MPa, making it highly capable for heavy vertical lifting tasks.
A key design trait of this SAILB variant is its asymmetric cushioning: the locker end features a 22.5mm variable air cushion, which is deliberately shorter than the 36mm cushion on the free end to accommodate the locking hardware. The standard carbon steel rod utilizes an M20x1.5 thread. For position sensing, you can mount AirTAC CMSE reed or DMSE electronic solid-state switches into the dual-side sensor grooves, provided a -S magnet is specified.
Airtac SAILB Rear Lock Cylinder SAILB80X250 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB80X250 |
|---|---|
| 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 SAILB80X250 Is Used
Vertical Lift Safety
Holds heavy elevated loads securely in the retracted position instantly upon air pressure loss, preventing sudden crashes on lifting machinery.
Power Failure Hold
Maintains the rod safely at the back stroke end during unexpected power or air supply outages, securing gates and heavy guards.
Clamp and Secure
Locks the retracted rod to keep clamps open and safely disengaged during machine loading, unloading, and changeover processes.
Is the Airtac SAILB Rear Lock Cylinder SAILB80X250 the Right Lock Cylinder?
Select this 80mm bore when a 63mm bore (providing 1559N push at 0.5 MPa) lacks the power to safely lift your load, but you want to avoid the larger footprint and higher air consumption of a 100mm bore (5497N at 0.7 MPa). Choose the SAILB configuration specifically when the load must be secured in the retracted position. If your application requires the rod to be held at an arbitrary mid-stroke point rather than the end of stroke, select the BSAI clamp-lock cylinder instead.
When integrating this 250mm stroke cylinder, use a side-load guide to prevent rod damage, as long strokes amplify lateral stress. The lock is a static holding device that engages after the piston stops; it is not a dynamic brake. Never use a fast-exhaust valve with this unit, as back-pressure on the locker side can unintentionally release the lock—always use an independent-exhaust solenoid valve. For human-safety critical overhead loads, add an independent mechanical safety measure. Replacement parts must match the 80mm bore, 250mm stroke, back locker position, PT port threads, and standard mounting options (Basic, FA, FB, CA, CB, CR, LB, TC, FTC, TCM1, TCM2).
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 SAILB80X250 FAQ
The 80mm bore generates 2513N push and 2268N pull at 0.5 MPa, 3518N push at 0.7 MPa, and 4523N push at 0.9 MPa, with a maximum force of 513 kgf at 1.0 MPa.
The lock is spring-applied and air-released, engaging only at the retracted stroke end. It unlocks automatically via air supply or manually via a lever. It is a static hold, not a mid-stroke clamp (use BSAI for that) or a dynamic brake.
Related AirTAC Lock & Standard Cylinders
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