This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X125SN, 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 SI40 Standard Cylinder SI40X125SN
The AirTAC Airtac SI40 Standard Cylinder SI40X125SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 125mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X125SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke125 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X125SN
- 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 SI40 Standard Cylinder SI40X125SN
The AirTAC SI40X125SN is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 125mm stroke. It delivers 628N push and 528N pull at 0.5MPa through a G1/4 port. The direct replacement is the SAI40X125SN, matching the exact interface, force, and mounting.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. It adds SAIL, SAIF, and BSAI variants absent from the SI line. The NBR seal handles -20 to +70C, while Viton H extends this to 150C.
Airtac SI40 Standard Cylinder SI40X125SN Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X125SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X125SN |
| Bore size | Ø40 mm |
| Stroke | 125 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| 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 – 800 mm/s |
| Cushion | Adjustable, 27 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI40X125SN carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
The SAI40X125SN produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI40 Standard Cylinder SI40X125SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×125 | 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 SI40 Standard Cylinder SI40X125SN Is Used
Component Clamping
Secures mid-weight machined parts during milling or drilling, utilizing the 628N push force at 0.5MPa for rigid workholding.
Package Diverting
Actuates sorting pop-up arms or gates on packaging lines, where the 125mm stroke provides precise lateral movement.
Pallet Stops
Controls pallet flow on roller conveyors by extending a 16mm rod to halt goods, relying on the 528N pull force for retraction.
Replacing the Airtac SI40 Standard Cylinder SI40X125SN with the SAI40X125SN
To replace the SI40X125SN, order the SAI40X125SN direct, confirming the ISO 15552 mounting interface, 125mm stroke, M12x1.25 rod thread, and G1/4 port (PT/G/NPT). Keep the -S magnet for CS1-B/DS1-B legacy sensors, which transition to current AirTAC switches on the SAI. The NBR seal is standard. For sizing, neighboring bores offer 982N (50mm) or 402N (32mm) push at 0.5MPa. Remember, a plain cylinder drifts without live air; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variants. At 125mm stroke, side-load risks are low, but always guide the load to prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X125SN
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI40 Standard Cylinder SI40X125SN FAQ
Yes, the AirTAC SI40X125SN is discontinued. The direct replacement is the SAI40X125SN. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 125mm stroke, G1/4 port, and mounting fixtures.
The 40mm bore features a G1/4 port and M12x1.25 rod thread. It delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa. Speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X125SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X125SN replacement — usually within 7-8 hours.