This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X125S, 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 SI125X125S
The AirTAC SI125 Standard Cylinder SI125X125S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 125mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X125S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke125 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X125S
- 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 SI125X125S
The AirTAC SI125X125S is a discontinued double-acting ISO 15552 profile cylinder featuring an extruded aluminum barrel, a 125 mm bore, and a 125 mm stroke. It delivers 6136 N of push force at 0.5 MPa. Because this legacy SI unit is end-of-life, AirTAC supplies the SAI125X125S as the direct replacement. It preserves the exact ISO 15552 mounting interface, 32 mm rod, M27x2 thread, G1/2 port, and output thrust, fitting existing fixtures perfectly.
The SAI upgrade incorporates an advanced piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also introduces lock and valve variants absent in the SI line, such as the SAIL air-released lock and BSAI clamp-lock. This -S model includes a piston magnet for legacy CS1-B/DS1-B sensors, though the SAI successor uses current AirTAC switches.
Airtac SI125 Standard Cylinder SI125X125S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X125S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X125S |
| Bore size | Ø125 mm |
| Stroke | 125 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 SAI125X125S 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 SAI125X125S 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 SI125X125S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×125 | 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 SI125X125S Is Used
Heavy-Duty Pressing
Ideal for applying high clamping forces in automated assembly lines, utilizing the 6136 N thrust at 0.5 MPa to seat bearings or form components securely.
Pallet Handling
Drives robust lifting and positioning mechanisms in packaging conveyors, where the 125 mm bore provides the necessary power to elevate heavy goods reliably.
Injection Mold Extraction
Executes positive part ejection from molding machinery, taking advantage of the adjustable 40 mm air cushions to decelerate heavy tooling at stroke ends.
Replacing the Airtac SI125 Standard Cylinder SI125X125S with the SAI125X125S
To replace the discontinued SI125X125S, order the SAI125X125S. Confirm the ISO 15552 mounting interface, the 125 mm bore, the 125 mm stroke, the G1/2 port, and your mounting accessory (such as LB foot or TC trunnion). The -S suffix indicates a magnet for position sensing; while the SI used CS1-B/DS1-B switches, the SAI replacement utilizes current AirTAC sensors. If your application requires less force, consider neighboring bores like the 100 mm option; if more force is needed, step up to the 160 mm bore. A plain cylinder does not hold load on air loss—the cushion only decelerates—so for load holding, specify the SAIL or BSAI lock variant, or use an external rod lock. Operating speed for this 125 mm bore is 30-500 mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X125S
- ✓ 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 SI125X125S FAQ
Yes, the SI125X125S is discontinued. The direct replacement is the AirTAC SAI125X125S. It is dimensionally interchangeable per ISO 15552, matching the 125 mm bore, 125 mm stroke, G1/2 port, and mounting interface, so it drops directly into existing fixtures.
The 125 mm bore features a G1/2 air port. It 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 maximum force of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X125S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X125S replacement — usually within 7-8 hours.