This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X8, 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 SI125X8
The AirTAC Airtac SI125 Standard Cylinder SI125X8 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 8mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X8, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke8 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X8
- 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 SI125X8
The AirTAC SI125X8 is a discontinued double-acting ISO 15552 profile cylinder with an 8 mm stroke. It delivers 6136 N push force at 0.5 MPa. The direct replacement is the SAI125X8, matching the bore, stroke, G1/2 port, and ISO 15552 mounting interface.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure. This SKU lacks a magnet, so it cannot take a sensor. For holding, use SAIL or BSAI lock variants.
Airtac SI125 Standard Cylinder SI125X8 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X8 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X8 |
| Bore size | Ø125 mm |
| Stroke | 8 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 SAI125X8 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 SAI125X8 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 SI125X8
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×8 | 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 SI125X8 Is Used
Short-Stroke Clamping
Ideal for high-force 6136 N clamping of heavy metal parts in machining fixtures using the 8 mm stroke.
Heavy Duty Pressing
Delivers 8590 N at 0.7 MPa for pressing bearings or pins in automated assembly lines over short distances.
End-of-Line Stopping
Acts as a robust stopper block for heavy pallets, utilizing the 125 mm bore and 32 mm rod to absorb impacts.
Replacing the Airtac SI125 Standard Cylinder SI125X8 with the SAI125X8
To replace the SI125X8, order the SAI125X8, confirming the ISO 15552 mounting, 125 mm bore, 8 mm stroke, and G1/2 port. This non-magnet SKU cannot accept a CS1-B/DS1-B sensor. Sizing both ways: a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore yields 10053 N. A plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X8
- ✓ 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 SI125X8 FAQ
Yes, the SI125X8 is discontinued. The direct replacement is the SAI125X8. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 8 mm stroke, output force, G1/2 port, and mounting interface.
This double-acting cylinder features a G1/2 port. It generates 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N at 0.9 MPa, and a theoretical max of 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X8
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X8 replacement — usually within 7-8 hours.