This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX270S, 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 SI40AX270S
The AirTAC Airtac SI40 Standard Cylinder SI40AX270S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 270mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX270S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke270 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX270S
- 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 SI40AX270S
The AirTAC SI40AX270S is a discontinued double-acting ISO 15552 profile cylinder featuring a 40mm bore, 270mm stroke, and a G1/4 air port. It delivers 628N push force at 0.5MPa. The direct replacement is the SAI40AX270S, which matches the exact mounting interface, bore, stroke, output force, and port size.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. This specific SI40AX270S includes the -A SUS420J2 stainless piston rod and -S magnet for legacy CS1-B/DS1-B switches. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI40 Standard Cylinder SI40AX270S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX270S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX270S |
| Bore size | Ø40 mm |
| Stroke | 270 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 SAI40AX270S 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 SAI40AX270S 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 SI40AX270S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×270 | 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 SI40AX270S Is Used
Mid-Tonnage Actuation
Drives 40mm bore clamping arms and medium-duty press fixtures requiring a 270mm travel distance and 628N of thrust at 0.5MPa.
Package Diversion
Powers sorting gates and pusher mechanisms on packaging lines, utilizing the 270mm stroke to clear standard conveyor widths.
Replacing the Airtac SI40 Standard Cylinder SI40AX270S with the SAI40AX270S
To replace this discontinued SI40AX270S, order the SAI40AX270S. Confirm the ISO 15552 mounting interface, the 40mm bore, 270mm stroke, G1/4 port (PT/G/NPT), and your specific mounting accessory. Retain the -S magnet for current AirTAC switches and the -A SUS420J2 stainless rod. If you need more force, the neighbouring 50mm bore yields 982N push at 0.5MPa; if less is required, the 32mm bore provides 402N. Because this is a 270mm stroke, ensure adequate guidance to prevent rod-bending side loads. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for load holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX270S
- ✓ 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 SI40AX270S FAQ
Yes, the SI40AX270S is discontinued. The direct replacement is the AirTAC SAI40AX270S. It is dimensionally interchangeable per the ISO 15552 mounting interface, maintaining the exact 40mm bore, 270mm stroke, 628N force, and G1/4 port to fit your existing fixtures.
The 40mm bore features a G1/4 air port and a 16mm rod. It generates 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical maximum force of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX270S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX270S replacement — usually within 7-8 hours.