This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X940S, 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 SI125X940S
The AirTAC SI125 Standard Cylinder SI125X940S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 940mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X940S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke940 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X940S
- 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 SI125X940S
The AirTAC SI125X940S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 940 mm stroke. It delivers 6136 N push force at 0.5 MPa through a G1/2 port. AirTAC replaced this legacy unit with the SAI125X940S, a direct upgrade sharing the exact ISO 15552 mounting interface, M27x2 rod thread, and 40 mm cushions.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked. This -S SKU includes a piston magnet for CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X940S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X940S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X940S |
| Bore size | Ø125 mm |
| Stroke | 940 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 SAI125X940S 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 SAI125X940S 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 SI125X940S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×940 | 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 SI125X940S Is Used
Heavy Material Transfer
Drives large pallets or heavy fixtures over 940 mm transitions where 6136 N push force easily overcomes cart inertia.
Large Assembly Press
Provides the 125 mm bore clamping thrust required to seat large automotive or industrial components over a long stroke.
Replacing the Airtac SI125 Standard Cylinder SI125X940S with the SAI125X940S
To replace the SI125X940S, order the SAI125X940S. Confirm your ISO 15552 mounting accessories (LB, FA, TC, etc.), the G1/2 port, and the -S magnet for legacy CS1-B/DS1-B switches (the SAI uses current AirTAC switches). If you need more force than the 6136 N at 0.5 MPa, step up to the 160 mm bore; if less is needed, the 100 mm bore provides 3927 N. Because the 940 mm stroke invites rod bending, use external guides to prevent side loads. A plain cylinder drifts without air; for load holding on air loss, specify the SAIL or BSAI lock variant, or use an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X940S
- ✓ 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 SI125X940S FAQ
Yes, the SI125X940S is discontinued. The direct replacement is the SAI125X940S. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 940 mm stroke, G1/2 port, and mounting interface.
It uses a G1/2 port. Force ratings are: 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 SAI125X940S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X940S replacement — usually within 7-8 hours.