This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX300S, 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 SI40AX300S
The AirTAC Airtac SI40 Standard Cylinder SI40AX300S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 300mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX300S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke300 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX300S
- 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 SI40AX300S
The AirTAC SI40AX300S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 300mm stroke. It delivers 628N push and 528N pull at 0.5MPa, features a G1/4 air port, and includes a SUS420J2 stainless piston rod (-A) alongside a built-in magnet (-S) for CS1-B/DS1-B legacy switches. AirTAC replaced this legacy unit with the SAI40AX300S, a direct replacement retaining the exact ISO 15552 mounting interface, bore, stroke, force, and port size.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life. The broader SAI family also adds SAIL, SAIF, and BSAI lock or self-valve variants absent in the SI line, while a Viton H seal option raises operating temperature to 0-150 C.
Airtac SI40 Standard Cylinder SI40AX300S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX300S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX300S |
| Bore size | Ø40 mm |
| Stroke | 300 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 SAI40AX300S 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 SAI40AX300S 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 SI40AX300S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×300 | 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 SI40AX300S Is Used
Stainless Rod Actuation
Leveraging the SUS420J2 piston rod for corrosion resistance, this 40mm bore unit drives medium-force clamping and positioning tasks in washdown or mildly corrosive industrial environments.
300mm Transfer Stroke
Providing a 628N push at 0.5MPa, the 300mm stroke handles part rejection and linear transfers between conveyor belts, requiring external guides to prevent rod bending over the extended length.
Replacing the Airtac SI40 Standard Cylinder SI40AX300S with the SAI40AX300S
To replace the SI40AX300S, order the SAI40AX300S. It drops directly into existing fixtures via the identical ISO 15552 mounting interface, matching the 40mm bore, 300mm stroke, G1/4 port, and M12x1.25 rod thread. Keep the -A stainless rod and -S magnet specifications; the SAI accepts current AirTAC switches instead of the legacy CS1-B/DS1-B sensors. When sizing, neighbouring bores offer different force classes: a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore provides 982N. Because this is a 300mm stroke, prevent rod bending by guiding the load externally to avoid side-load forces. A plain cylinder drifts without live air and its cushions only decelerate; for load holding, use an external pilot check valve or explore the SAIL and BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX300S
- ✓ 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 SI40AX300S FAQ
Yes, the AirTAC SI40AX300S is discontinued. The direct replacement is the SAI40AX300S. It shares the identical ISO 15552 mounting interface, 40mm bore, 300mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly while upgrading the piston seal.
This double-acting cylinder features a G1/4 air port and delivers a push force of 628N and a pull force of 528N at 0.5MPa. At 0.7MPa the push force is 879N, reaching 1130N at 0.9MPa, with a theoretical maximum of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX300S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX300S replacement — usually within 7-8 hours.