This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X500S, 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 SI40X500S
The AirTAC SI40 Standard Cylinder SI40X500S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 500mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X500S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke500 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X500S
- 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 SI40X500S
The AirTAC SI40X500S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 500 mm stroke. Delivering 628 N push force at 0.5 MPa, it features a G1/4 port, M12x1.25 rod thread, and a built-in piston magnet for legacy CS1-B/DS1-B switches. AirTAC replaced this EOL unit with the SAI40X500S.
The SAI40X500S is a direct replacement sharing the exact ISO 15552 mounting interface, bore, stroke, output force, and porting. It upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI40 Standard Cylinder SI40X500S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X500S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X500S |
| Bore size | Ø40 mm |
| Stroke | 500 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 SAI40X500S 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 SAI40X500S 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 SI40X500S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×500 | 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 SI40X500S Is Used
Long-Stroke Diversion
Pushes packages across transfer lines with a 500 mm reach, utilizing the 628 N push force at 0.5 MPa to overcome guide friction.
Component Ejection
Ejects machined parts from a fixture over a long distance, relying on adjustable 27 mm air cushions to decelerate at stroke end.
Replacing the Airtac SI40 Standard Cylinder SI40X500S with the SAI40X500S
To replace the SI40X500S, order the SAI40X500S direct equivalent, confirming the ISO 15552 interface, 40 mm bore, 500 mm stroke, G1/4 port (PT/G/NPT thread options), and mounting accessory. The -S magnet equates to legacy CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches. Sizing both ways: a 32 mm bore yields 402 N push at 0.5 MPa, whereas a 50 mm bore yields 982 N. For this 500 mm stroke, use external guides to prevent rod bending and side-load damage. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X500S
- ✓ 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 SI40X500S FAQ
Yes, the SI40X500S is discontinued. The direct replacement is the SAI40X500S. It shares the identical ISO 15552 mounting interface, 40 mm bore, 500 mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly while upgrading the piston seal.
The 40 mm bore features a G1/4 air port. Force ratings are: 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 maximum of 128 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X500S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X500S replacement — usually within 7-8 hours.