Airtac SAILB Rear Lock Cylinder SAILB63X250S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB63X250S is a genuine double-acting ISO 15552 profile cylinder with a Ø63mm 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.
- BoreØ63 mm
- Stroke250 mm
- Port sizeG3/8
- Lock positionBack cover
- Rod threadM16×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB63X250S
The AirTAC SAILB63X250-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, it automatically engages a lock pin to hold the rod securely at the retracted stroke end whenever release air is cut, ensuring your load stays put without live pressure. This 63mm bore size generates 1559N of push force and 1402N of pull force at 0.5 MPa, making it a robust choice for mid-weight holding tasks.
This specific unit includes a magnet for position sensing and is wired for AirTAC CMSE reed and DMSE electronic sensors. A key design trait of the SAIL series is that the variable air cushion at the locker end is shorter (21mm) than the free end (30mm) to accommodate the locking hardware. Furthermore, this is a static holding brake that engages only after the piston stops, not a mid-stroke clamp or dynamic brake.
Airtac SAILB Rear Lock Cylinder SAILB63X250S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB63X250S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø63 mm |
| Stroke | 250 mm |
| Acting type | Double acting, with lock |
| Port size | G3/8 |
| Rod thread | M16×1.5 |
| 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 (30 mm free end / 21 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 (Ø63mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 1559 N | 1402 N |
| 0.7 MPa | 2182 N | — |
| Max (@1.0 MPa) | 318 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 SAILB63X250S Is Used
Vertical Lift Safety
Holds a raised vertical load securely at the retracted stroke end the moment air pressure drops, preventing sudden crashes on pneumatic lifts.
Clamp and Hold
Maintains consistent clamping force on a workpiece at the stroke terminal without consuming continuous compressed air during the machining cycle.
Gate Positioning
Secures heavy safety gates or machine guards in the closed position using a mechanical pin, releasing only when control air is actively supplied.
Is the Airtac SAILB Rear Lock Cylinder SAILB63X250S the Right Lock Cylinder?
Select this back-lock model when your mechanism must retain a load safely at the fully retracted position upon power loss. If your application requires holding the load at the extended end instead, choose the SAILF version; if you need to freeze the rod at an arbitrary intermediate point, step up to the BSAI clamp-lock cylinder instead. For sizing, stepping down to a 50mm bore drops the 0.5 MPa push force to 982N, while upgrading to an 80mm bore increases it to 2513N.
When integrating this lock cylinder, avoid using fast-exhaust valves and opt for an independent-exhaust solenoid valve, as back-pressure on the locker side can inadvertently release the lock. Always add an independent mechanical safety measure if human safety depends on the load remaining up. With a 250mm stroke, use rigid guide rails to prevent side-load deflection. To match this unit exactly, ensure your replacement has a 63mm bore, 250mm stroke, PT tapered ports, a back locker, 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 SAILB63X250S FAQ
At 0.5 MPa, this 63mm bore cylinder provides 1559N of push force and 1402N of pull force. If operated at 0.7 MPa, the push force increases to 2182N.
The lock is spring-applied and air-released, engaging a pin to hold the rod statically at the retracted stroke end when air is cut. You can unlock it by supplying release air or using the manual lever. It does not clamp at mid-stroke.
Related AirTAC Lock & Standard Cylinders
Request a Quote for Airtac SAILB Rear Lock Cylinder SAILB63X250S
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.