This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX45, 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 SI125AX45
The AirTAC Airtac SI125 Standard Cylinder SI125AX45 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 45mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX45, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke45 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX45
- 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 SI125AX45
The AirTAC SI125AX45 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 45 mm stroke. It delivers 6136 N push force at 0.5 MPa through a G1/2 port. AirTAC replaced this legacy unit with the SAI125AX45, a direct sharing the exact ISO 15552 mounting interface, bore, output force, and port size. The SAI upgrade features a modernized piston seal using two Y-shaped one-way elements for low start-up pressure and extended life.
This specific SKU uses an SUS420J2 stainless steel piston rod for corrosion resistance and lacks a magnet, meaning it cannot accept position sensors. For load holding, note that the air cushion only decelerates the piston near stroke end and will not hold a load without live air; consider the SAIL lock variant or an external pilot check valve.
Airtac SI125 Standard Cylinder SI125AX45 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX45 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX45 |
| Bore size | Ø125 mm |
| Stroke | 45 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 SAI125AX45 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 SAI125AX45 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 SI125AX45
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×45 | 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 SI125AX45 Is Used
Heavy-Duty Pressing
Applies 6136 N of thrust at 0.5 MPa for seating large bearings and forming heavy components in automated machinery.
High-Force Ejection
Ejects molded parts from presses, relying on the SUS420J2 stainless rod to resist corrosion in humid environments.
Replacing the Airtac SI125 Standard Cylinder SI125AX45 with the SAI125AX45
To replace the discontinued SI125AX45, order the SAI125AX45. Confirm the ISO 15552 mounting interface, the 125 mm bore, the 45 mm stroke, and the G1/2 port. Because this SKU has no -S magnet, it cannot support legacy CS1-B/DS1-B sensors; order a magnet-equipped version if sensing is required. This bore produces 6136 N push at 0.5 MPa (1251 kgf max at 1.0 MPa); if you need less force, step down to a 100 mm bore (3927 N push), or step up to 160 mm (10053 N push) for heavier loads. For applications needing self-contained locking, explore the SAIL air-released lock or BSAI clamp-lock variants. Remember that a standard cylinder drifts without air pressure, so use a pilot check valve for load holding. The stroke is under 300 mm, so rod-bending side loads are minimal, but always guide the load to prevent binding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX45
- ✓ 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 SI125AX45 FAQ
Yes, the AirTAC SI125AX45 is discontinued. The direct replacement is the SAI125AX45. It is dimensionally interchangeable per ISO 15552, maintaining the same 125 mm bore, 45 mm stroke, output force, G1/2 port, and mounting interface. The SAI features an upgraded piston seal with two Y-shaped one-way elements for longer life and lower start-up pressure.
This double-acting cylinder uses a G1/2 port and a 32 mm rod. It generates 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. Operating speed ranges from 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX45
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX45 replacement — usually within 7-8 hours.