Airtac SAILB Rear Lock Cylinder SAILB125X1000S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB125X1000S is a genuine double-acting ISO 15552 profile cylinder with a Ø125mm bore, 1000mm 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
- Stroke1000 mm
- Port sizeG1/2
- Lock positionBack cover
- Rod threadM27×2
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB125X1000S
The AirTAC SAILB125X1000-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 secures the rod at the retracted stroke-end the moment release air is cut, holding the load safely without live pressure. A 125mm bore generates 6136N of push force at 0.5MPa, making it suited for heavy vertical lifting tasks.
This variant includes a magnet for position sensing with CMSE reed or DMSE electronic switches. The carbon steel rod provides robust side-load resistance, and the PT tapered ports ensure a tight pneumatic seal. Note that the variable air cushion at the locker end is 24mm, intentionally shorter than the 40mm cushion on the free end to accommodate the locking hardware.
Airtac SAILB Rear Lock Cylinder SAILB125X1000S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB125X1000S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø125 mm |
| Stroke | 1000 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 SAILB125X1000S Is Used
Vertical Lift Safety
Holds heavy raised platforms securely at the retracted stroke end during a sudden air pressure loss.
Clamp and Hold
Maintains high-force clamping pressure on heavy parts at the rod-in position without consuming air.
Gate and Door Control
Secures large industrial loading dock doors in the closed position until air is actively supplied.
Is the Airtac SAILB Rear Lock Cylinder SAILB125X1000S the Right Lock Cylinder?
Choose this 125mm bore when a 100mm bore (providing 3927N push at 0.5MPa) lacks the power to lift your load, but a 160mm bore is oversized. Select the SAILB back-lock configuration to hold the load in the retracted position; choose SAILF instead if the extended rod-out position must be secured. If your application requires clamping at an arbitrary mid-stroke point rather than the stroke end, use a BSAI clamp-lock cylinder instead.
The lock is a static holding device that engages after the cylinder stops, not a dynamic brake for a moving rod. Never use a fast-exhaust valve with this cylinder, as back-pressure on the locker side can inadvertently release the lock; use an independent-exhaust solenoid valve. At a 1000mm stroke, the lever arm amplifies side loads, so external guide rails are strongly recommended. For human safety, always add an independent mechanical safety measure. Replacement matches require the exact 125mm bore, 1000mm stroke, back locker, PT port, and -S magnet.
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 SAILB125X1000S FAQ
At 0.5MPa, the 125mm bore provides 6136N of push force and 5734N of pull force. At 0.7MPa, the push force increases to 8590N.
The lock is spring-applied and air-released, engaging only at the retracted stroke-end after the rod stops. It is a static hold, not a dynamic brake. Unlock by supplying air to the release port or using the manual lever.
Related AirTAC Lock & Standard Cylinders
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