This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX275S, 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 SI40AX275S
The AirTAC Airtac SI40 Standard Cylinder SI40AX275S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 275mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX275S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke275 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX275S
- 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 SI40AX275S
The AirTAC SI40AX275S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 275mm stroke. Featuring a SUS420J2 stainless piston rod and a built-in magnet for CS1-B/DS1-B switches, it delivers 628 N push force at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI40AX275S, a direct sharing the exact ISO 15552 mounting interface, bore, stroke and output force.
The SAI upgrade introduces an advanced piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note that a standard cylinder drifts without live air; the cushion only decelerates. For secure holding, explore the SAIL or BSAI lock variants.
Airtac SI40 Standard Cylinder SI40AX275S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX275S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX275S |
| Bore size | Ø40 mm |
| Stroke | 275 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 SAI40AX275S 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 SAI40AX275S 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 SI40AX275S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×275 | 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 SI40AX275S Is Used
Stainless Rod Actuation
Leverages the SUS420J2 rod for mid-force (628 N) positioning in environments where standard carbon steel faces corrosion risks.
275mm Stroke Diverting
Provides the extended travel needed to push or redirect packages between parallel conveyor lanes using the 40mm bore class.
Replacing the Airtac SI40 Standard Cylinder SI40AX275S with the SAI40AX275S
To replace the discontinued SI40AX275S, order the SAI40AX275S. Verify your ISO 15552 mounting fixtures, the G1/4 air port, M12x1.25 rod thread, and the -S magnet requirement. The SAI family also adds SAIF (integrated valve) and SAIL/BSAI lock variants absent in the SI line. If downsizing, a 32mm bore yields 402 N push at 0.5 MPa; if upsizing, a 50mm bore provides 982 N. Because the 275mm stroke exceeds 300mm, ensure adequate guide support to prevent rod bending and side-load wear. Remember, a plain cylinder does not hold load without air; use an external rod lock or pilot check valve for vertical applications.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX275S
- ✓ 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 SI40AX275S FAQ
Yes, the SI40AX275S is discontinued. The direct replacement is the SAI40AX275S. It shares the identical ISO 15552 mounting interface, 40mm bore, 275mm stroke, G1/4 port, and output force, fitting directly into your existing fixtures.
The bore is 40mm with a G1/4 air port. At 0.5 MPa it provides 628 N push and 528 N pull force. At 0.7 MPa push is 879 N, and at 0.9 MPa it is 1130 N. The theoretical maximum force is 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX275S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX275S replacement — usually within 7-8 hours.