This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X1780S, with the same bore, stroke, output force, port and mounting, so it fits the same application. The SAI replacement keeps the same ISO 15552 mounting interface, bore, stroke, output force and accessories, so it drops straight into existing fixtures. It is the current-production version of this cylinder with an upgraded piston seal.
Airtac SI125 Standard Cylinder SI125X1780S
The AirTAC SI125 Standard Cylinder SI125X1780S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 1780mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X1780S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke1780 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X1780S
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac SI125 Standard Cylinder SI125X1780S
The AirTAC SI125X1780S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 1780 mm stroke. Generating 6136 N push force at 0.5 MPa, it is replaced directly by the SAI125X1780S. This direct successor matches the G1/2 port, M27x2 thread, and mounting interface, fitting existing fixtures seamlessly. Stroke 1780 mm exceeds the 1500 mm standard maximum, making it a non-standard made-to-order item.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and longevity. The SAI family also adds SAIL, SAIF, and BSAI lock variants absent in the SI line. Your SI125X1780S includes a magnet for CS1-B/DS1-B switches, though the SAI uses current AirTAC sensors.
Airtac SI125 Standard Cylinder SI125X1780S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X1780S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X1780S |
| Bore size | Ø125 mm |
| Stroke | 1780 mm |
| Acting type | Double acting |
| Port size | G1/2 |
| Rod thread | M27×2.0 |
| Fluid | Air (filtered by 40µm element) |
|---|---|
| Operating pressure | 0.15 – 1.0 MPa |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 500 mm/s |
| Cushion | Adjustable, 40 mm |
| Max standard stroke | Up to 1500 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI125X1780S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
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 | |
The SAI125X1780S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI125 Standard Cylinder SI125X1780S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×1780 | Stroke length in mm. |
| -S | Optional built-in magnet for sensor position sensing. |
Legacy SI-family variants: SID (double rod), SIJ (adjustable stroke) — each maps to its SAI equivalent (SID→SAID, SIJ→SAIJ). Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B).
Where the Airtac SI125 Standard Cylinder SI125X1780S Is Used
Long-Stroke Material Pusher
Drives heavy workpieces across 1.78-meter conveyor transfers using 6136 N of thrust, requiring external guide rails to prevent rod bending.
High-Force Pallet Divert
Actuates large pallet routing gates in logistics lines, taking advantage of the 125 mm bore force and robust G1/2 air supply.
Automated Press Clamping
Secures heavy steel components for machining operations, providing reliable clamping up to 11045 N at 0.9 MPa operating pressure.
Replacing the Airtac SI125 Standard Cylinder SI125X1780S with the SAI125X1780S
To replace the SI125X1780S, order the SAI125X1780S, confirming the ISO 15552 mounting interface, G1/2 port, and magnet option. Sizing both ways: a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore yields 10053 N. This 125 mm bore gives 6136 N push and 5734 N pull at 0.5 MPa, reaching 8590 N at 0.7 MPa. Operating speed is 30-500 mm/s. Because 1780 mm exceeds the 1500 mm standard stroke, it is non-standard and requires external guides to prevent rod bending under side loads. A plain cylinder drifts without air; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X1780S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI125 Standard Cylinder SI125X1780S FAQ
Yes, the SI125X1780S is discontinued. The direct replacement is the SAI125X1780S. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 1780 mm stroke, G1/2 port, and mounting interface. You simply order the SAI equivalent.
The 125 mm bore features a G1/2 port. It generates 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, and 11045 N push at 0.9 MPa. The theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X1780S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X1780S replacement — usually within 7-8 hours.