This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X155, 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 SI125X155
The AirTAC Airtac SI125 Standard Cylinder SI125X155 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 SAI125X155, 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 → SAI125X155
- 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 SI125X155
The AirTAC SI125X155 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 155 mm stroke, delivering 6136 N push force at 0.5 MPa. The direct replacement is the SAI125X155, which matches the exact ISO 15552 mounting interface, G1/2 port, and M27x2 rod thread. Because this SKU lacks the -S magnet, it cannot accept a position sensor.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL and BSAI lock variants absent from the legacy line.
Airtac SI125 Standard Cylinder SI125X155 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X155 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X155 |
| 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 SAI125X155 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 SAI125X155 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 SI125X155
| 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 SI125X155 Is Used
Heavy Press Operations
Drives substantial forming and stamping presses requiring up to 8590 N of thrust at 0.7 MPa over a 155 mm working distance.
Bulk Material Diversion
Actuates heavy-duty diverter arms on high-throughput packaging lines, benefiting from the 30-500 mm/s speed range.
Replacing the Airtac SI125 Standard Cylinder SI125X155 with the SAI125X155
To replace the SI125X155, order the SAI125X155 ensuring your ISO 15552 mounting accessory (LB foot, FA flange, or TC trunnion) and G1/2 port match. If you need position sensing, select an SAI125X155S instead, as this no-S SKU cannot take a sensor. Sizing both ways: the 125 mm bore yields 6136 N push at 0.5 MPa, while the neighbouring 100 mm bore offers 3927 N. A plain cylinder drifts on air loss—the cushion only decelerates—so use a pilot check valve or the SAIL lock variant for load holding. At 155 mm stroke, side-load is minimal, but always guide the rod to prevent bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X155
- ✓ 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 SI125X155 FAQ
Yes, the AirTAC SI125X155 is discontinued. The direct replacement is the SAI125X155. It is dimensionally interchangeable per the ISO 15552 mounting interface, retaining the same 125 mm bore, 155 mm stroke, output force, and G1/2 port so it fits existing fixtures directly.
This double-acting cylinder uses a G1/2 air port. 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 of 1251 kgf at 1.0 MPa. It operates at 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X155
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X155 replacement — usually within 7-8 hours.