Airtac SAILB Rear Lock Cylinder SAILB40X350S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB40X350S is a genuine double-acting ISO 15552 profile cylinder with a Ø40mm 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.
- BoreØ40 mm
- Stroke350 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM12×1.25
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB40X350S
The AirTAC SAILB40X350-S is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the back cover. This lock safely holds the rod at the retracted stroke end without requiring live air pressure. In the 40mm bore class, it generates 628N of push and 528N of pull thrust at 0.5 MPa, making it ideal for compact power-failure safety applications. Equipped with a magnet (-S), it supports AirTAC CMSE reed and DMSE electronic sensors for precise position detection.
Because the lock occupies the rear end, the variable air cushion on that locker end is shortened to 20mm, compared to 27mm on the free front end. The standard carbon steel rod provides durable service, and the unit utilizes PT tapered port threads. For unlocking, operators can supply air to the release port for automatic operation or use the manual release lever during maintenance.
Airtac SAILB Rear Lock Cylinder SAILB40X350S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB40X350S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø40 mm |
| Stroke | 350 mm |
| Acting type | Double acting, with lock |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| 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 (27 mm free end / 20 mm lock end) |
| Max stroke | Up to 1200 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 (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 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 SAILB40X350S Is Used
Vertical Retract Safety
Secures vertical loads in the retracted position during a power loss, preventing sudden drops when air pressure is cut off.
Clamp and Hold
Maintains solid clamping force at the retracted stroke end without consuming continuous compressed air, saving energy.
Gate Safety Hold
Keeps safety gates and guards locked in the closed position until the release air is actively supplied to the back cover port.
Is the Airtac SAILB Rear Lock Cylinder SAILB40X350S the Right Lock Cylinder?
Select this 40mm bore model when an application demands secure load holding at the retracted position; if your process requires the load to be held extended instead, choose the SAILF40X350-S front-locker variant. If the mechanism needs to clamp and hold at an arbitrary mid-stroke point rather than a stroke end, the BSAI clamp-lock cylinder is the correct choice. To match this unit exactly for replacement, verify the 40mm bore, 350mm stroke, back locker position, PT port threads, and the -S magnet option. Given the 350mm stroke, ensure external guide rails are used to prevent excessive side-loading on the rod.
Remember that the SAIL lock is a static holding device that engages after the cylinder stops, not a dynamic brake for a moving rod. Valve selection is critical: never use a fast-exhaust valve with this cylinder, as back-pressure on the locker side can inadvertently release the lock. Always use an independent-exhaust solenoid valve, and if human safety depends on the load staying retracted, add an independent mechanical safety measure as well.
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 SAILB40X350S FAQ
At 0.5 MPa operating pressure, the 40mm bore provides 628N of push force and 528N of pull force. At 0.7 MPa, the push force increases to 879N.
The lock is spring-applied and air-released, located in the back cover to hold the rod securely at the retracted stroke end. It unlocks automatically when air is supplied to the release port, or manually via a lever. It is a static hold only and will not stop a moving rod.
Related AirTAC Lock & Standard Cylinders
Request a Quote for Airtac SAILB Rear Lock Cylinder SAILB40X350S
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.