This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X250, 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 SI125X250
The AirTAC SI125 Standard Cylinder SI125X250 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 250mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X250, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke250 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X250
- 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 SI125X250
The AirTAC SI125X250 is a discontinued double-acting ISO 15552 profile cylinder. It delivers 6136 N push force at 0.5 MPa through a 125 mm bore and 250 mm stroke. AirTAC replaced this legacy unit with the SAI125X250 direct replacement, matching the exact G1/2 port, M27x2 rod thread, and ISO 15552 mounting interface.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. Note this non-magnet SKU cannot take a sensor.
Airtac SI125 Standard Cylinder SI125X250 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X250 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X250 |
| Bore size | Ø125 mm |
| Stroke | 250 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 SAI125X250 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 SAI125X250 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 SI125X250
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×250 | 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 SI125X250 Is Used
Heavy Stamping Press
Drives large platens and heavy dies requiring 6136 N thrust at 0.5 MPa with robust 32 mm rod stability.
Bulk Material Divert
Actuates heavy lane diverters on high-capacity packaging lines at 30-500 mm/s operating speeds.
Replacing the Airtac SI125 Standard Cylinder SI125X250 with the SAI125X250
To replace the SI125X250, order the SAI125X250. Confirm the ISO 15552 mounting interface, 250 mm stroke, and G1/2 port (PT/G/NPT). This non-magnet version cannot accept CS1-B/DS1-B sensors; order an -S SAI if sensing is needed. Sizing down, an 80 mm bore yields 2513 N push at 0.5 MPa; sizing up, a 160 mm bore yields 10053 N. The 32 mm rod handles high thrust, but for 250 mm strokes check guide bearings to prevent rod bending. Air cushions (40 mm) decelerate loads but do not hold position; use a SAIL lock, BSAI clamp-lock, or external pilot check valve for secure load holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X250
- ✓ 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 SI125X250 FAQ
Yes, the AirTAC SI125X250 is discontinued. The direct replacement is the SAI125X250, offering the same 125 mm bore, 250 mm stroke, G1/2 port, and ISO 15552 mounting interface for existing fixtures.
The 125 mm bore uses a G1/2 port. It generates 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 theoretical max of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X250
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X250 replacement — usually within 7-8 hours.