This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X290S, 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 SI40X290S
The AirTAC Airtac SI40 Standard Cylinder SI40X290S 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 SAI40X290S, 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 → SAI40X290S
- 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 SI40X290S
The AirTAC SI40X290S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 290 mm stroke. It delivers 628 N push force at 0.5 MPa through a G1/4 port. The direct replacement is the SAI40X290S, matching the bore, stroke, force, port, and ISO 15552 mounting interface for existing fixtures.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked. This -S model has a piston magnet for legacy CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40X290S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X290S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X290S |
| 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 SAI40X290S 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 SAI40X290S 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 SI40X290S
| 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 SI40X290S Is Used
Package Diversion
Pushes medium-weight cartons on packaging lines using the 628 N push force at 0.5 MPa.
Clamp Actuation
Drives mid-sized holding clamps on machining fixtures, utilizing the 290 mm stroke length.
Replacing the Airtac SI40 Standard Cylinder SI40X290S with the SAI40X290S
To replace the SI40X290S, order the SAI40X290S. Confirm the ISO 15552 mounting interface, 40 mm bore, 290 mm stroke, G1/4 port (PT/G/NPT), and mounting accessory. The -S suffix means a magnet is present for CS1-B/DS1-B switches. For sizing, a 50 mm bore gives 982 N push at 0.5 MPa, while a 32 mm bore gives 402 N. At 290 mm stroke, use a guide to prevent rod bending and side loads. 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 → SAI40X290S
- ✓ 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 SI40X290S FAQ
Yes, the SI40X290S is discontinued. The direct replacement is the SAI40X290S. It is dimensionally interchangeable per ISO 15552, matching the 40 mm bore, 290 mm stroke, 628 N force, G1/4 port, and mounting interface.
The 40 mm bore delivers 628 N push and 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, and a theoretical max of 128 kgf at 1.0 MPa. Operating speed is 30-800 mm/s. It features a 16 mm rod, M12x1.25 thread, and 27 mm cushions.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X290S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X290S replacement — usually within 7-8 hours.