This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X402S, 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 SI125X402S
The AirTAC SI125 Standard Cylinder SI125X402S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 402mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X402S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke402 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X402S
- 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 SI125X402S
The AirTAC SI125X402S is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 402mm stroke. Delivering 6136N push force at 0.5MPa via a G1/2 port, it is replaced by the direct replacement SAI125X402S. This upgrade keeps the exact ISO 15552 mounting interface, bore, and output force, fitting existing fixtures perfectly.
The SAI successor introduces an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. It also expands options with SAIL, SAIF, and BSAI variants absent from the SI line. The built-in magnet supports legacy CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X402S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X402S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X402S |
| Bore size | Ø125 mm |
| Stroke | 402 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 SAI125X402S 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 SAI125X402S 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 SI125X402S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×402 | 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 SI125X402S Is Used
Heavy Press Clamping
Secures large metal castings during machining operations, utilizing the 6136N push force at 0.5MPa to hold components rigidly against cutting loads.
Pallet Diverting
Actuates heavy-duty routing gates on high-capacity assembly lines, where the 5734N pull force reliably retracts the diverter mechanism under friction.
Large Lift Gates
Raises and lowers bulk material handling barriers, benefiting from the adjustable 40mm air cushions to decelerate the substantial gate mass smoothly.
Replacing the Airtac SI125 Standard Cylinder SI125X402S with the SAI125X402S
To replace the SI125X402S, order the SAI125X402S. Verify the ISO 15552 mounting interface, 125mm bore, 402mm stroke, G1/2 port, and M27x2 rod thread. Because this is a 402mm stroke, add external guides to prevent rod bending and side-load wear. Sizing down, an 80mm bore yields 2513N [email protected]; sizing up, a 160mm bore yields 10053N. The standard cushion is 40mm. A plain cylinder drifts without air; for load holding, use an external pilot check valve or the SAIL/BSAI lock variant. The -S magnet works with CS1-B/DS1-B switches.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X402S
- ✓ 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 SI125X402S FAQ
Yes, the SI125X402S is discontinued. The direct replacement is the SAI125X402S. It shares the same ISO 15552 mounting interface, 125mm bore, 402mm stroke, output force, and G1/2 port, fitting directly into existing machinery.
The G1/2 port feeds a 32mm rod delivering 6136N push and 5734N pull at 0.5MPa. At 0.7MPa push is 8590N, and 11045N at 0.9MPa. Theoretical max force is 1251kgf at 1.0MPa, operating at 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X402S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X402S replacement — usually within 7-8 hours.