This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X290STC, 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 SI40X290STC
The AirTAC Airtac SI40 Standard Cylinder SI40X290STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 290mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X290STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke290 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X290STC
- 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 SI40X290STC
The AirTAC SI40X290STC is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 290mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the direct replacement SAI40X290STC. The SAI upgrade features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life, while keeping the exact ISO 15552 mounting interface.
This TC trunnion mounted unit includes a piston magnet for CS1-B/DS1-B sensors. Note that a plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Airtac SI40 Standard Cylinder SI40X290STC Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X290STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X290STC |
| Bore size | Ø40 mm |
| Stroke | 290 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 SAI40X290STC 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 SAI40X290STC 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 SI40X290STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×290 | 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 SI40X290STC Is Used
Package Diversion
Ideal for pushing medium-weight cartons off a main belt line using the 628N push force and 290mm travel distance.
Component Ejection
Ejects machined parts from a fixture with reliable 528N pull force, utilizing the TC trunnion to handle pivot stresses.
Pallet Stopper
Acts as a pneumatic stop for incoming pallets, safely decelerating the load using the adjustable 27mm air cushions.
Replacing the Airtac SI40 Standard Cylinder SI40X290STC with the SAI40X290STC
To replace the discontinued SI40X290STC, order the SAI40X290STC. Confirm the ISO 15552 TC trunnion interface, 40mm bore, 290mm stroke, G1/4 port, and the -S magnet for CS1-B/DS1-B switches. Sizing both ways: a neighboring 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. At 290mm stroke, add a guide to prevent rod bending and side-load wear. A plain cylinder does not hold load without live air; the cushion only decelerates. For held loads, use an external rod lock, pilot check valve, or the SAIL/BSAI variants. The SAIF variant adds a built-in valve if needed.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X290STC
- ✓ 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 SI40X290STC FAQ
Yes, the SI40X290STC is discontinued. The direct replacement is the SAI40X290STC. It shares the same ISO 15552 mounting interface, 40mm bore, 290mm stroke, G1/4 port, and TC trunnion, fitting existing fixtures perfectly.
This double-acting cylinder has a G1/4 air port. The force ratings are: 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 SAI40X290STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X290STC replacement — usually within 7-8 hours.