This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX145S, 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 SI125AX145S
The AirTAC SI125 Standard Cylinder SI125AX145S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 145mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX145S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke145 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX145S
- 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 SI125AX145S
The AirTAC SI125AX145S is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 145mm stroke. It delivers 6136N push force at 0.5MPa through a G1/2 port. AirTAC replaced it with the SAI125AX145S, a direct upgrade sharing the same interface, force, and mounting. The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. It also uses a SUS420J2 stainless piston rod for corrosion resistance.
The built-in magnet supports legacy CS1-B/DS1-B switches. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants the SAI family added.
Airtac SI125 Standard Cylinder SI125AX145S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX145S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX145S |
| Bore size | Ø125 mm |
| Stroke | 145 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 SAI125AX145S 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 SAI125AX145S 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 SI125AX145S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×145 | 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 SI125AX145S Is Used
Heavy Press Clamping
Secures large metal castings during machining operations, utilizing the 6136N push force to hold components rigidly against the fixture.
Automated Welding Arm
Positions heavy welding heads into exact alignment on automotive assembly lines, relying on the 32mm SUS420J2 stainless rod.
Replacing the Airtac SI125 Standard Cylinder SI125AX145S with the SAI125AX145S
To replace the SI125AX145S, order the SAI125AX145S. Confirm the ISO 15552 mounting interface, 125mm bore, 145mm stroke, G1/2 port (PT/G/NPT thread), and mounting accessory. The -S magnet enables CS1-B/DS1-B sensors (the SAI uses current AirTAC switches). If downsizing, the 100mm bore yields 3927N push at 0.5MPa; if upsizing, the 160mm bore yields 10053N. Because stroke is under 300mm, rod-bending side loads are minimal. For dead-load holding, the cushion only decelerates; add a pilot check valve, external rod lock, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX145S
- ✓ 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 SI125AX145S FAQ
Yes, the SI125AX145S is discontinued. The direct replacement is the SAI125AX145S. It shares the same ISO 15552 mounting interface, 125mm bore, 145mm stroke, output force, and G1/2 port, fitting existing fixtures perfectly.
The 125mm bore cylinder features a G1/2 port. At 0.5 MPa it provides 6136N push and 5734N pull force. At 0.7 MPa push is 8590N, and at 0.9 MPa it is 11045N. The theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX145S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX145S replacement — usually within 7-8 hours.