This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X280, 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 SI125X280
The AirTAC Airtac SI125 Standard Cylinder SI125X280 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 280mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X280, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke280 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X280
- 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 SI125X280
The AirTAC SI125X280 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 280 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. Because this legacy unit lacks the -S magnet option, it cannot accept position sensors. AirTAC replaced it with the SAI125X280, a direct upgrade retaining the exact ISO 15552 mounting interface, M27x2 rod thread, and 40 mm cushions.
The SAI125X280 introduces an upgraded piston seal featuring two Y-shaped one-way elements for lower start-up pressure and longer life. If high-temperature operation is needed, Viton H seals extend the range to 150 C.
Airtac SI125 Standard Cylinder SI125X280 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X280 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X280 |
| Bore size | Ø125 mm |
| Stroke | 280 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 SAI125X280 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 SAI125X280 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 SI125X280
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×280 | 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 SI125X280 Is Used
Heavy Press Clamping
Secures large metal stampings in automated press lines, utilizing the 6136 N push force at 0.5 MPa to hold workpieces firmly during machining.
Injection Mould Ejection
Drives heavy ejection plates in plastic injection moulding setups, where the 280 mm stroke provides full extraction of deep-cavity parts.
Pallet Stopper Arms
Acts as a robust stopper mechanism on high-capacity conveyor lines, absorbing kinetic impact from loaded pallets using adjustable 40 mm cushions.
Replacing the Airtac SI125 Standard Cylinder SI125X280 with the SAI125X280
To replace the SI125X280, order the SAI125X280 and verify your ISO 15552 mounting fixtures, G1/2 port, and M27x2 rod thread. Since this specific SKU has no magnet, it cannot support CS1-B/DS1-B sensors; choose an -S SAI variant if sensing is required. At 280 mm stroke, guide external rods to prevent side-loading and rod-bending under heavy lateral forces. For sizing down, a 100 mm bore yields 3927 N at 0.5 MPa; sizing up to 160 mm provides 10053 N. Note that a standard cylinder drifts without live air—the cushion only decelerates. For load holding, specify the SAIL lock or BSAI clamp-lock variant, or use an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X280
- ✓ 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 SI125X280 FAQ
Yes, the SI125X280 is discontinued. The direct replacement is the AirTAC SAI125X280. It shares the exact ISO 15552 mounting interface, 125 mm bore, 280 mm stroke, output force, and G1/2 port, fitting existing fixtures perfectly.
It features a G1/2 air port and M27x2 rod thread. Force output is 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N push at 0.9 MPa, with a theoretical max of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X280
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X280 replacement — usually within 7-8 hours.