This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X395S, 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 SI125X395S
The AirTAC SI125 Standard Cylinder SI125X395S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 395mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X395S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke395 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X395S
- 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 SI125X395S
The AirTAC SI125X395S is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore and 395mm stroke. It delivers 6136N push force at 0.5MPa via a G1/2 port. AirTAC replaced this legacy unit with the SAI125X395S, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, output force and porting.
The SAI successor introduces an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also adds SAIL, SAIF and BSAI lock variants the SI lacked. Your -S suffix denotes a piston magnet for legacy CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X395S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X395S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X395S |
| Bore size | Ø125 mm |
| Stroke | 395 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 SAI125X395S 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 SAI125X395S 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 SI125X395S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×395 | 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 SI125X395S Is Used
Heavy Press Clamping
Secures large automotive stampings or heavy machinery chassis during machining, utilising the 6136N push force at 0.5MPa to hold components rigidly against cutting loads.
Bulk Material Diversion
Actuates heavy-duty deflector gates on aggregate or mining conveyor lines, where the robust 125mm bore and adjustable 40mm cushions absorb high kinetic energy at stroke ends.
Replacing the Airtac SI125 Standard Cylinder SI125X395S with the SAI125X395S
To replace the SI125X395S, order the SAI125X395S. Confirm the ISO 15552 mounting accessory (LB, FA, CA, TC), the G1/2 port thread (PT/G/NPT) and the -S magnet. Sizing both ways: neighbouring 100mm bore yields 3927N push at 0.5MPa, while 160mm yields 10053N. This 125mm bore provides 6136N push and 5734N pull at 0.5MPa. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, specify the SAIL or BSAI lock variant, or use an external pilot check valve. With a 395mm stroke, use external guides to prevent rod bending and side-load wear. Rod options include carbon steel, SUS420J2 (A) or SUS304 (B).
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X395S
- ✓ 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 SI125X395S FAQ
Yes, the SI125X395S is discontinued. The direct replacement is the SAI125X395S. It features the same ISO 15552 mounting interface, 125mm bore, 395mm stroke, output force and G1/2 port, fitting directly into existing fixtures.
It uses a G1/2 port. Theoretical forces are 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a maximum of 1251kgf at 1.0MPa. Operating speed is 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X395S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X395S replacement — usually within 7-8 hours.