This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X225S, 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 SI125X225S
The AirTAC SI125 Standard Cylinder SI125X225S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 225mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X225S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke225 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X225S
- 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 SI125X225S
The AirTAC SI125X225S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 225 mm stroke. It delivers 6136 N push and 5734 N pull force at 0.5 MPa, utilizing a G1/2 port and M27x2 rod thread. AirTAC replaced this legacy unit with the SAI125X225S, a direct replacement sharing the exact ISO 15552 mounting interface, bore, stroke, force, port and mounting accessories.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The SI125X225S includes a piston magnet for legacy CS1-B/DS1-B sensors, while the SAI family also introduces SAIL, SAIF, and BSAI lock variants absent in the original SI line.
Airtac SI125 Standard Cylinder SI125X225S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X225S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X225S |
| Bore size | Ø125 mm |
| Stroke | 225 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 SAI125X225S 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 SAI125X225S 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 SI125X225S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×225 | 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 SI125X225S Is Used
Heavy Press Operations
Drives robust pressing and stamping fixtures requiring up to 11045 N of thrust at 0.9 MPa, utilizing the 225 mm stroke to form heavy-gauge materials.
Large Mold Handling
Indexes heavy injection molds and tooling along production lines, relying on the rigid ISO 15552 profile barrel and 32 mm rod for stability.
Replacing the Airtac SI125 Standard Cylinder SI125X225S with the SAI125X225S
To replace the discontinued SI125X225S, order the SAI125X225S. Confirm the ISO 15552 mounting interface, the 125 mm bore, 225 mm stroke, G1/2 port (PT/G/NPT thread options), and the -S magnet requirement for current AirTAC switches (legacy used CS1-B/DS1-B). Sizing context: a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore yields 10053 N. This 125 mm unit provides 6136 N at 0.5 MPa and 11045 N at 0.9 MPa. A plain cylinder does not hold load on air loss; the air cushion only decelerates near stroke end. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. Rod material options include carbon steel, SUS420J2 (A), and SUS304 (B).
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X225S
- ✓ 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 SI125X225S FAQ
Yes, the SI125X225S is discontinued. The direct replacement is the SAI125X225S. It shares the same ISO 15552 mounting interface, 125 mm bore, 225 mm stroke, output force, G1/2 port, and mounting accessories, fitting directly into existing fixtures.
The 125 mm bore cylinder delivers 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, and a theoretical max of 1251 kgf at 1.0 MPa. The operating speed is 30-500 mm/s, with a 40 mm adjustable air cushion at both ends.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X225S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X225S replacement — usually within 7-8 hours.