Airtac SAILB Rear Lock Cylinder SAILB125X75
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB125X75 is a genuine double-acting ISO 15552 profile cylinder with a Ø125mm bore, 75mm 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
- Stroke75 mm
- Port sizeG1/2
- Lock positionBack cover
- Rod threadM27×2
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB125X75
The AirTAC SAILB125X75 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock in the back cover. It securely holds the retracted rod position without requiring live air pressure. In the 125mm bore class, it provides substantial thrust, delivering 8590N of push force and 5734N of pull force at 0.7 MPa.
The integrated lock engages statically after the piston stops at the stroke end, distinguishing it from a dynamic brake. A notable design detail is the variable air cushion at the locker end, which is engineered shorter (24mm) compared to the free end (40mm) to accommodate the locking hardware. The standard carbon steel rod supports robust side-load handling across the full ISO 15552 mounting interface.
Airtac SAILB Rear Lock Cylinder SAILB125X75 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB125X75 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø125 mm |
| Stroke | 75 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 SAILB125X75 Is Used
Vertical Load Holding
Secures lifted heavy payloads in the retracted position during power loss, preventing sudden drops.
Safety Gate Lock
Holds heavy safety gates and machine guards firmly closed at the stroke end without continuous air consumption.
Clamp and Hold
Maintains high-force clamping pressure on large workpieces at the retracted end while machining operations proceed.
Is the Airtac SAILB Rear Lock Cylinder SAILB125X75 the Right Lock Cylinder?
Choose this 125mm bore when an application demands high force alongside fail-safe load holding at the retracted stroke end. If your thrust requirements are lower, stepping down to the 80mm bore yields 3518N of push force at 0.7 MPa. Select the SAILF variant if the load must be secured at the extended stroke end, or switch to the BSAI clamp-lock if you need to hold the rod at an arbitrary mid-stroke position.
For replacements, match the 125mm bore, 75mm stroke, back locker position, PT tapered ports, and the appropriate mounting accessory. Note that the SAIL lock is a static holding device, not a moving-rod brake. Valve selection is critical: never use a fast-exhaust valve, as back-pressure on the locker side can unintentionally release the lock; always use an independent-exhaust solenoid valve. If human safety depends on the load remaining elevated, 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 SAILB125X75 FAQ
The 125mm bore generates 6136N of push force and 5734N of pull force at 0.5 MPa, scaling up to 8590N push and 5734N pull at 0.7 MPa.
The lock is spring-applied and air-released, engaging statically after the rod stops at the retracted stroke end. It unlocks automatically via air supply to the release port or manually via the lever.
Related AirTAC Lock & Standard Cylinders
Request a Quote for Airtac SAILB Rear Lock Cylinder SAILB125X75
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.