This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX375, 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 SI125AX375
The AirTAC SI125 Standard Cylinder SI125AX375 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 375mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX375, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke375 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX375
- 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 SI125AX375
The AirTAC SI125AX375 is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 375mm stroke. It delivers 6136N push and 5734N pull at 0.5MPa via a G1/2 port. The direct replacement is the SAI125AX375, matching the interface, force and stroke. This SKU lacks a magnet (-S), so it cannot accept a CS1-B/DS1-B sensor.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. It also adds SAIL, SAIF and BSAI variants the SI lacked. The -A rod is SUS420J2 stainless steel.
Airtac SI125 Standard Cylinder SI125AX375 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX375 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX375 |
| Bore size | Ø125 mm |
| Stroke | 375 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 SAI125AX375 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 SAI125AX375 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 SI125AX375
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×375 | 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 SI125AX375 Is Used
Heavy Press Clamping
Applies up to 8590N at 0.7MPa to secure large metal castings during CNC machining operations.
Mold Ejection Systems
Uses the 375mm stroke to push heavy industrial molds completely out of hydraulic presses.
Replacing the Airtac SI125 Standard Cylinder SI125AX375 with the SAI125AX375
To replace the SI125AX375, order the SAI125AX375. Confirm the ISO 15552 mounting interface, 375mm stroke, G1/2 port (PT/G/NPT), M27x2 thread and SUS420J2 stainless rod. Because this SKU has no magnet, it cannot take a switch; order an -S suffix if sensing is needed. For sizing, a 100mm bore yields 3927N at 0.5MPa, while a 160mm bore yields 10053N. A plain cylinder drifts on air loss—the cushion only decelerates—so use a SAIL lock or external pilot check valve for load holding. At 375mm, prevent rod bending by using an external guide to absorb side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX375
- ✓ 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 SI125AX375 FAQ
Yes, the SI125AX375 is discontinued. The direct replacement is the SAI125AX375. It is dimensionally interchangeable per ISO 15552, retaining the same 125mm bore, 375mm stroke, force, G1/2 port and mounting accessories.
It features a G1/2 port, M27x2 rod thread and a 32mm rod. Force output is 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a theoretical max of 1251kgf at 1.0MPa. Operating speed is 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX375
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX375 replacement — usually within 7-8 hours.