This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X120S, 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 SI40X120S
The AirTAC Airtac SI40 Standard Cylinder SI40X120S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 120mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X120S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke120 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X120S
- 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 SI40X120S
The AirTAC SI40X120S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore, 120mm stroke, and a G1/4 air port. It delivers 628 N of push force at 0.5 MPa. AirTAC replaced this legacy unit with the SAI40X120S, a direct sharing the exact ISO 15552 mounting interface, bore, stroke, output force, and porting.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. The SAI family also adds SAIL, SAIF, and BSAI lock or valve variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40X120S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X120S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X120S |
| Bore size | Ø40 mm |
| Stroke | 120 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 SAI40X120S 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 SAI40X120S 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 SI40X120S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×120 | 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 SI40X120S Is Used
Package Diverting
Actuates routing gates on 40mm bore conveyors, providing 628 N push at 0.5 MPa to deflect cartons at line speed.
Clamp Actuation
Secures medium workpieces in machining fixtures, using the 528 N pull force at 0.5 MPa to hold parts firmly.
Replacing the Airtac SI40 Standard Cylinder SI40X120S with the SAI40X120S
To replace this SI40X120S with the SAI40X120S, verify the ISO 15552 mounting interface, 40mm bore, 120mm stroke, G1/4 port (PT/G/NPT thread), and your mounting accessory. Because this is a double-acting cylinder, a plain unit does NOT hold load on air loss—the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. If sizing both ways, a 32mm bore yields 402 N push at 0.5 MPa, while a 50mm bore yields 982 N. This 120mm stroke is under the 300mm side-load risk threshold, but always guide rigid loads to prevent rod bending. The SAI also offers Viton H seals for high heat and SUS304 stainless rods.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X120S
- ✓ 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 SI40X120S FAQ
Yes, the AirTAC SI40X120S is discontinued. The direct replacement is the SAI40X120S. It shares the identical ISO 15552 mounting interface, 40mm bore, 120mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
The 40mm bore features a G1/4 air port and a 16mm rod. Force output is 628 N push and 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, 1130 N push at 0.9 MPa, and a theoretical max of 128 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X120S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X120S replacement — usually within 7-8 hours.