This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X440, 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 SI125X440
The AirTAC SI125 Standard Cylinder SI125X440 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 440mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X440, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke440 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X440
- 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 SI125X440
The AirTAC SI125X440 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 440 mm stroke, delivering 6136 N push force at 0.5 MPa. The direct replacement is the SAI125X440, retaining the exact ISO 15552 mounting interface, G1/2 port, and M27x2 rod thread for seamless fixture integration.
The SAI upgrade features a refined piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this specific SKU lacks a magnet and cannot accept position sensors; the legacy SI -S variants used CS1-B/DS1-B switches.
Airtac SI125 Standard Cylinder SI125X440 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X440 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X440 |
| Bore size | Ø125 mm |
| Stroke | 440 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 SAI125X440 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 SAI125X440 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 SI125X440
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×440 | 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 SI125X440 Is Used
Heavy Press Forming
Ideal for driving large press dies requiring substantial push force, utilizing the 6136 N thrust at 0.5 MPa to form heavy-gauge materials reliably.
Large Component Indexing
Shifts heavy industrial components along assembly lines, taking advantage of the 125 mm bore and adjustable 40 mm cushions to stop loads smoothly.
Replacing the Airtac SI125 Standard Cylinder SI125X440 with the SAI125X440
To replace the SI125X440, order the SAI125X440, confirming the ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/2 port, and the 440 mm stroke. Because this non-magnet SKU cannot host a sensor, if detection is needed you must select an SAI125X440S and use current AirTAC switches. For sizing, neighboring bores offer alternatives: the 100 mm bore yields 3927 N push at 0.5 MPa, while the 160 mm bore provides 10053 N. At 0.7 MPa this 125 mm bore outputs 8590 N. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding specify an external pilot check valve or the SAIL/BSAI lock variant. Finally, at 440 mm stroke, prevent rod bending by guiding the load externally to avoid side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X440
- ✓ 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 SI125X440 FAQ
Yes, the SI125X440 is discontinued. The direct replacement is the SAI125X440. It is dimensionally interchangeable per ISO 15552, matching the bore, stroke, force, G1/2 port, and mounting interface.
The G1/2 port bore provides 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N at 0.9 MPa, and a max force of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X440
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X440 replacement — usually within 7-8 hours.