This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X500STC, 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 SI40X500STC
The AirTAC Airtac SI40 Standard Cylinder SI40X500STC 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 SAI40X500STC, 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 → SAI40X500STC
- 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 SI40X500STC
The AirTAC SI40X500STC is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 500mm stroke. It delivers 628 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40X500STC, a direct upgrade retaining the exact ISO 15552 mounting interface, TC trunnion mount, and output force.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The -S magnet supports legacy CS1-B/DS1-B sensors, while the SAI family adds SAIL lock, SAIF valve, and BSAI clamp-lock variants the SI lacked.
Airtac SI40 Standard Cylinder SI40X500STC Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X500STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X500STC |
| 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 SAI40X500STC 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 SAI40X500STC 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 SI40X500STC
| 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 SI40X500STC Is Used
Long-Stroke Diversion
Pushes packages across transfer lines with 628 N force at 0.5 MPa, utilizing the 500mm stroke to bridge adjacent conveyor belts.
Actuator Positioning
Shifts tooling carriages along machining centers, relying on the TC trunnion mount to accommodate alignment shifts during motion.
Replacing the Airtac SI40 Standard Cylinder SI40X500STC with the SAI40X500STC
To replace the SI40X500STC, order the SAI40X500STC. Confirm the ISO 15552 TC trunnion interface, 40mm bore, 500mm stroke, G1/4 port (PT/G/NPT thread options), and the -S magnet for current AirTAC switches. For sizing, a 32mm bore yields 402 N push at 0.5 MPa, while a 50mm bore yields 982 N. Note that a plain cylinder drifts on air loss—the cushion only decelerates near stroke end—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for held loads. Because the 500mm stroke invites rod bending, use an external guide to prevent side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X500STC
- ✓ 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 SI40X500STC FAQ
Yes, the SI40X500STC is discontinued. The direct replacement is the SAI40X500STC. It matches the ISO 15552 mounting interface, 40mm bore, 500mm stroke, output force, and G1/4 port size, fitting existing fixtures perfectly.
The G1/4 port feeds a 40mm bore that generates 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. The rod is 16mm with an M12x1.25 thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X500STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X500STC replacement — usually within 7-8 hours.