This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X520, 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 SI125X520
The AirTAC SI125 Standard Cylinder SI125X520 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 520mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X520, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke520 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X520
- 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 SI125X520
The AirTAC SI125X520 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 520 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. The direct replacement is the SAI125X520, matching the interface, bore, stroke, force, and mounting. Because this SKU lacks the -S magnet, it cannot accept a position switch.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. The SAI family also adds SAIL and BSAI lock variants absent from the SI line.
Airtac SI125 Standard Cylinder SI125X520 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X520 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X520 |
| Bore size | Ø125 mm |
| Stroke | 520 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 SAI125X520 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 SAI125X520 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 SI125X520
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×520 | 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 SI125X520 Is Used
Heavy Stamp Press Feed
Drives robust 520 mm strokes to feed thick plate material into stamping presses, utilizing the 6136 N thrust at 0.5 MPa.
Large Mold Actuation
Shifts heavy industrial molds along the 520 mm travel path, requiring external guides to prevent rod bending under load.
Replacing the Airtac SI125 Standard Cylinder SI125X520 with the SAI125X520
To replace the SI125X520, order the SAI125X520, confirming the ISO 15552 mounting interface, 125 mm bore, 520 mm stroke, G1/2 port (PT/G/NPT), and mounting accessory. This non-magnet SKU cannot take a sensor; if sensing is needed, specify an SAI with the -S magnet for CS1-B/DS1-B switches. 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—so use an external rod lock or pilot check valve for holding. At 520 mm, prevent rod bending by adding external guides to manage side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X520
- ✓ 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 SI125X520 FAQ
Yes, the SI125X520 is discontinued. The direct replacement is the SAI125X520, matching the ISO 15552 mounting interface, 125 mm bore, 520 mm stroke, force, and G1/2 port.
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, 11045 N at 0.9 MPa, and a theoretical max of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X520
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X520 replacement — usually within 7-8 hours.