This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X120, 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 SI125X120
The AirTAC SI125 Standard Cylinder SI125X120 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 120mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X120, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke120 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X120
- 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 SI125X120
The AirTAC SI125X120 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 120 mm stroke. It delivers 6136 N push force at 0.5 MPa through a G1/2 port. The direct replacement is the SAI125X120, which shares identical mounting, output, and porting dimensions.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and longevity. Note this specific SKU lacks a magnet (-S), meaning it cannot accept CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X120 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X120 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X120 |
| Bore size | Ø125 mm |
| Stroke | 120 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 SAI125X120 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 SAI125X120 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 SI125X120
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×120 | 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 SI125X120 Is Used
Heavy Pressing
Applies 6136 N of thrust at 0.5 MPa for seating heavy bearings or forming robust components in automated machinery.
Clamp Fixtures
Secures large workpieces in machining centers where high rigidity and 125 mm bore output are required.
Replacing the Airtac SI125 Standard Cylinder SI125X120 with the SAI125X120
To replace the SI125X120, order the SAI125X120 keeping the identical ISO 15552 interface, 125 mm bore, 120 mm stroke, and G1/2 port (PT/G/NPT). Confirm your mounting accessory (LB, FA, TC, etc.) and remember this non-magnet version cannot host a sensor. For sizing, neighboring bores offer different forces: the 100 mm bore gives 3927 N push at 0.5 MPa, while the 160 mm bore yields 10053 N. A plain cylinder drifts without live air; the cushion only decelerates. For load holding, use an external pilot check valve, rod lock, or the SAIL/BSAI lock variants. The SAI family also adds the SAIF valve variant, though only for bores 32-100.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X120
- ✓ 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 SI125X120 FAQ
Yes, the SI125X120 is discontinued. The direct replacement is the SAI125X120. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 120 mm stroke, G1/2 port, and mounting interface.
The 125 mm bore features a G1/2 port and M27x2 rod thread. It provides 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 max of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X120
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X120 replacement — usually within 7-8 hours.