This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X370S, 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 SI125X370S
The AirTAC SI125 Standard Cylinder SI125X370S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 370mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X370S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke370 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X370S
- 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 SI125X370S
The AirTAC SI125X370S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 370 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. The direct replacement is the SAI125X370S, retaining identical mounting, force, and stroke dimensions.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure. If high heat is needed, Viton H seals raise the range to 150 C.
Airtac SI125 Standard Cylinder SI125X370S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X370S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X370S |
| Bore size | Ø125 mm |
| Stroke | 370 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 SAI125X370S 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 SAI125X370S 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 SI125X370S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×370 | 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 SI125X370S Is Used
Heavy Press Actuation
Drives large stamping or forming presses requiring 6136 N of push force at 0.5 MPa with a 370 mm travel distance.
Large Mold Handling
Positions heavy injection molds along the 370 mm stroke, relying on external guides to prevent rod bending.
Replacing the Airtac SI125 Standard Cylinder SI125X370S with the SAI125X370S
To replace the SI125X370S, order the SAI125X370S and confirm the ISO 15552 mounting interface, 370 mm stroke, G1/2 port, and M27x2 rod thread. The built-in magnet (-S) works with legacy CS1-B/DS1-B sensors, though the SAI family uses current AirTAC switches. For sizing, a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore yields 10053 N. Because this is a 370 mm stroke, use external guides to prevent rod bending and side-load damage. The air cushion only decelerates; it does not hold load on air loss, so add a pilot check valve or the SAIL/BSAI lock variant for suspended loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X370S
- ✓ 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 SI125X370S FAQ
Yes, the SI125X370S is discontinued. The direct replacement is the SAI125X370S. It is dimensionally interchangeable per ISO 15552, matching the 125 mm bore, 370 mm stroke, 6136 N force, G1/2 port, and mounting interface.
At 0.5 MPa, push force is 6136 N and pull is 5734 N. At 0.7 MPa push is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical max is 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X370S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X370S replacement — usually within 7-8 hours.