This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X40SN, 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 SI125X40SN
The AirTAC SI125 Standard Cylinder SI125X40SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 40mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X40SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke40 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X40SN
- 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 SI125X40SN
The AirTAC SI125X40SN is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 40 mm stroke. It delivers 6136 N push force at 0.5 MPa through a G1/2 port. AirTAC replaced this legacy unit with the SAI125X40SN, a direct replacement retaining the exact ISO 15552 mounting interface, M27x2 rod thread, and 40 mm cushions. The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life.
This -SN variant includes a piston magnet for CS1-B/DS1-B switches and NBR seals rated for -20 to +70 C (Viton H raises this to 150 C). Note that plain cylinders drift without live air; for load holding, explore the SAIL or BSAI lock variants.
Airtac SI125 Standard Cylinder SI125X40SN Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X40SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X40SN |
| Bore size | Ø125 mm |
| Stroke | 40 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 SAI125X40SN 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 SAI125X40SN 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 SI125X40SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×40 | 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 SI125X40SN Is Used
Heavy-Duty Pressing
Applies 6136 N of thrust at 0.5 MPa for seating large bearings or forming heavy gauge sheet metal components.
Pallet Stop Actuation
Short 40 mm stroke extends a robust 32 mm rod to halt loaded pallets securely on high-capacity conveyor lines.
Industrial Clamp Locking
Generates over 8500 N at 0.7 MPa to rigidly clamp heavy steel castings during machining operations.
Replacing the Airtac SI125 Standard Cylinder SI125X40SN with the SAI125X40SN
To replace the discontinued SI125X40SN, order the SAI125X40SN. Confirm the ISO 15552 mounting interface, 125 mm bore, 40 mm stroke, G1/2 port, and your specific mounting accessory. The -S magnet enables CS1-B/DS1-B sensors, while the -N denotes NBR seals. For sizing, a 100 mm bore offers 3927 N push at 0.5 MPa, whereas a 160 mm bore provides 10053 N. This 40 mm stroke is well below the 1500 mm maximum, so side-load rod-bending risks are minimal. For load holding on air loss, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants, as cushions only decelerate.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X40SN
- ✓ 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 SI125X40SN FAQ
Yes, the SI125X40SN is discontinued. The direct replacement is the SAI125X40SN, which matches the ISO 15552 mounting interface, bore, stroke, force, and G1/2 port. You can install it directly into existing fixtures.
It features a G1/2 air port and delivers 6136 N push and 5734 N pull at 0.5 MPa. At 0.7 MPa push is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X40SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X40SN replacement — usually within 7-8 hours.