This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X240S, 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 SI125X240S
The AirTAC SI125 Standard Cylinder SI125X240S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 240mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X240S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke240 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X240S
- 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 SI125X240S
The AirTAC SI125X240S is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore and a 240mm non-standard stroke. Delivering 6136N push force at 0.5MPa, it utilizes a G1/2 port and M27x2 rod thread. AirTAC replaced this legacy unit with the SAI125X240S, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, and output force.
The SAI upgrade features a refined piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. For applications needing load holding on air loss, the new SAI family introduces SAIL and BSAI lock variants absent in the SI line.
Airtac SI125 Standard Cylinder SI125X240S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X240S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X240S |
| Bore size | Ø125 mm |
| Stroke | 240 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 SAI125X240S 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 SAI125X240S 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 SI125X240S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×240 | 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 SI125X240S Is Used
Heavy Pressing
Applies the 6136N push force at 0.5MPa for seating large bearings and heavy mechanical assemblies in automotive tooling.
Material Forming
Drives robust 240mm stroke clamping motions in large-scale injection molding and heavy industrial forming lines.
Replacing the Airtac SI125 Standard Cylinder SI125X240S with the SAI125X240S
To replace the SI125X240S, order the SAI125X240S to retain the exact ISO 15552 interface, 125mm bore, 240mm stroke, G1/2 port, and mounting accessories. Because 240mm is a non-standard stroke, confirm the exact extended length dimensions for your fixture. The -S magnet supports legacy CS1-B/DS1-B sensors, which transition to current AirTAC switches on the SAI. For sizing, a neighboring 100mm bore yields 3927N push at 0.5MPa, while a 160mm bore yields 10053N. Note that a plain cylinder drifts without live air; for load holding, specify the SAIL lock or an external pilot check valve. At 240mm, ensure guide rails carry side loads to prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X240S
- ✓ 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 SI125X240S FAQ
Yes, the AirTAC SI125X240S is discontinued. The direct replacement is the SAI125X240S. It shares the identical ISO 15552 mounting interface, 125mm bore, 240mm stroke, output force, G1/2 port, and mounting accessories, fitting directly into existing fixtures.
The 125mm bore features a G1/2 port and M27x2 rod thread. Force output is 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a theoretical maximum of 1251kgf at 1.0MPa. Operating speed is 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X240S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X240S replacement — usually within 7-8 hours.