This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX350, 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 SI125AX350
The AirTAC SI125 Standard Cylinder SI125AX350 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 350mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX350, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke350 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX350
- 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 SI125AX350
The AirTAC SI125AX350 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 350 mm stroke. It delivers 6136 N push and 5734 N pull at 0.5 MPa, utilizing a G1/2 port and an M27x2 rod thread. As an end-of-line product, it is replaced by the SAI125AX350 direct upgrade, which maintains the exact ISO 15552 mounting interface, output force, and dimensions.
The SAI successor introduces an upgraded piston seal featuring two Y-shaped one-way elements for low start-up pressure and extended life. This SKU has no magnet (-A denotes the SUS420J2 stainless rod, not sensing) and cannot accept a switch.
Airtac SI125 Standard Cylinder SI125AX350 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX350 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX350 |
| Bore size | Ø125 mm |
| Stroke | 350 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 SAI125AX350 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 SAI125AX350 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 SI125AX350
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×350 | 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 SI125AX350 Is Used
Heavy-Duty Pressing
Applies 6136 N of thrust at 0.5 MPa for seating heavy bearings or forming thick materials over a 350 mm travel distance.
Pallet Lift Stations
Drives robust vertical lifting mechanisms.
Large Part Diversion
Actuates heavy diverter arms or sorting gates on high-capacity packaging lines, utilizing the 30-500 mm/s speed range.
Replacing the Airtac SI125 Standard Cylinder SI125AX350 with the SAI125AX350
To replace the SI125AX350, order the SAI125AX350. Confirm the ISO 15552 mounting fixture matches your choice of LB, FA, TC, or CA accessories, and verify the G1/2 port. Because this SKU lacks the -S magnet, it cannot support legacy CS1-B/DS1-B sensors; order an SAI with -S if position detection is needed. Sizing alternatives: step down to an 80 mm bore for lighter loads, or step up to 160 mm if you need more force. At 0.5 MPa, the 125 mm bore yields 6136 N push, while the 160 mm bore yields 10053 N. For this 350 mm stroke, use external guides to prevent rod bending and side-load wear. Note that a standard cylinder drifts on air loss; for load holding, specify the SAIL or BSAI lock variant, or use an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX350
- ✓ 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 SI125AX350 FAQ
Yes, the SI125AX350 is discontinued. The direct replacement is the SAI125AX350. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 350 mm stroke, G1/2 port, and mounting accessories.
It features a G1/2 air port. The force output is 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 of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX350
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX350 replacement — usually within 7-8 hours.