Airtac SAILB Rear Lock Cylinder SAILB80X125S
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB80X125S is a genuine double-acting ISO 15552 profile cylinder with a Ø80mm bore, 125mm 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
- Stroke125 mm
- Port sizeG3/8
- Lock positionBack cover
- Rod threadM20×1.5
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB80X125S
The AirTAC SAILB80X125-S is a double-acting ISO 15552 profile cylinder with a built-in mechanical lock in the back cover. Because the lock is spring-applied and air-released, cutting the release air drives a lock pin into the carbon steel rod, securely holding the load at the retracted stroke end without requiring live pressure. In the 80mm bore class, it generates 2513N of push thrust and 2268N of pull thrust at 0.5MPa, making it well-suited for heavy vertical lifting tasks.
This unit includes a magnet (-S) for position sensing with AirTAC CMSE reed or DMSE solid-state switches. A notable mechanical detail is that the variable air cushion at the locker end is shorter (22.5mm) than the free end (36mm). The cushion decelerates the piston near stroke termination, but only the mechanical lock actually sustains the load. You can unlock automatically via air supply or manually via the release lever.
Airtac SAILB Rear Lock Cylinder SAILB80X125S Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB80X125S |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø80 mm |
| Stroke | 125 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 SAILB80X125S Is Used
Vertical Lift Safety
Holds heavy elevated platforms securely in the retracted position instantly upon air pressure loss, preventing sudden drops.
Machine Guard Hold
Keeps safety gates locked in the open, retracted state during maintenance until control air is deliberately restored.
Clamp and Hold
Maintains retracted tooling position on machining centers during cycle interruptions without consuming continuous compressed air.
Is the Airtac SAILB Rear Lock Cylinder SAILB80X125S the Right Lock Cylinder?
Choose this 80mm bore when 50mm bore cylinders (offering 982N push at 0.5MPa) lack the force to hold your load, but a 100mm bore (3927N at 0.5MPa) would be physical overkill. Select this SAILB configuration when the machinery must remain safely retracted during a power loss. If your process requires holding the load at an arbitrary mid-stroke position rather than the stroke terminal, you must use a BSAI clamp-lock cylinder instead.
Remember that this lock is a static holding device that engages after the cylinder stops, not a dynamic brake for a moving rod. Avoid using fast-exhaust valves with this cylinder; use an independent-exhaust solenoid valve because back-pressure on the locker side can inadvertently release the lock. For safety-critical suspended loads, add an independent safety measure. To replace this unit, match the 80mm bore, 125mm stroke, back locker position, PT 3/8 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 SAILB80X125S FAQ
At 0.5MPa, this 80mm bore cylinder provides 2513N of push force and 2268N of pull force. At 0.7MPa, the push force increases to 3518N.
The lock is spring-applied and air-released, engaging only when the piston reaches the retracted stroke end in the back cover. It provides a static hold after the rod stops, not a dynamic brake. Unlocking is achieved automatically by supplying release air or manually via the release lever.
Related AirTAC Lock & Standard Cylinders
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