This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX155, 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 SI125AX155
The AirTAC Airtac SI125 Standard Cylinder SI125AX155 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 155mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX155, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke155 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX155
- 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 SI125AX155
The AirTAC SI125AX155 is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 155mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. The direct replacement is the SAI125AX155, retaining the same interface, M27x2 thread, and 40mm cushions.
This SKU features a SUS420J2 stainless steel rod but lacks a magnet, so it cannot accept position switches. The SAI upgrade uses two Y-shaped piston seals for low start-up pressure.
Airtac SI125 Standard Cylinder SI125AX155 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX155 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX155 |
| Bore size | Ø125 mm |
| Stroke | 155 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 SAI125AX155 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 SAI125AX155 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 SI125AX155
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×155 | 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 SI125AX155 Is Used
Heavy Press Operations
Drives robust pressing and forming jigs where the 6136 N push force at 0.5 MPa is required to seat or stake large components securely.
Pallet Handling
Actuates heavy-duty diverters and lifting stops in automated storage systems, moving substantial loads with a 313 kg vertical lift capacity.
Injection Molding Extraction
Extracts large molded parts from machinery, utilizing the SUS420J2 stainless rod to resist environmental moisture and maintain operational integrity.
Replacing the Airtac SI125 Standard Cylinder SI125AX155 with the SAI125AX155
To replace the SI125AX155, order the SAI125AX155. Confirm the ISO 15552 mounting fixture, 155mm stroke, G1/2 port, and SUS420J2 rod. Since this SKU has no magnet, you cannot mount legacy CS1-B/DS1-B sensors; if sensing is needed, specify an SAI with an S suffix. For load holding, note that standard cushions only decelerate; use an external pilot check valve or the SAIL/BSAI lock variants. Neighbouring bores: 100mm offers 3927 N push at 0.5 MPa, while 160mm offers 10053 N. At 0.7 MPa, this 125mm bore outputs 8590 N.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX155
- ✓ 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 SI125AX155 FAQ
Yes, the AirTAC SI125AX155 is discontinued. The direct replacement is the SAI125AX155. It is dimensionally interchangeable per ISO 15552, matching the 125mm bore, 155mm stroke, G1/2 port, and mounting interface.
It features a G1/2 port and delivers 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, and a theoretical maximum of 1251 kgf at 1.0 MPa. The rod is 32mm with an M27x2 thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX155
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX155 replacement — usually within 7-8 hours.