This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX300, 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 SI40AX300
The AirTAC Airtac SI40 Standard Cylinder SI40AX300 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 SAI40AX300, 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 → SAI40AX300
- 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 SI40AX300
The AirTAC SI40AX300 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 300mm stroke. It delivers 628 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40AX300, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. The -A suffix indicates a SUS420J2 stainless piston rod for corrosion resistance. Note this SKU lacks a magnet, so it cannot accept CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40AX300 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX300 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX300 |
| 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 SAI40AX300 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 SAI40AX300 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 SI40AX300
| 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 SI40AX300 Is Used
Package Diversion
Actuates routing gates on packaging lines where the 628 N push force easily deflects standard cartons.
Corrosive Fluid Dosing
The SUS420J2 stainless rod handles humid or mildly chemical washdown environments in dosing rigs.
Replacing the Airtac SI40 Standard Cylinder SI40AX300 with the SAI40AX300
To replace the SI40AX300, order the SAI40AX300. Verify your ISO 15552 mounting fixtures (LB, FA, TC, etc.), the G1/4 air port, and the M12x1.25 rod thread. Because this SKU has no -S magnet, it cannot support position sensing; if switches are needed, select an SAI40X300S. When sizing, the 40mm bore yields 628 N push at 0.5 MPa. If less force is acceptable, a 32mm bore provides 402 N; if more is required, a 50mm bore offers 982 N. For this 300mm stroke, use external guides to prevent rod bending and side-load wear. The standard cylinder does not hold load without live air; for load holding, consider an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX300
- ✓ 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 SI40AX300 FAQ
Yes, the SI40AX300 is discontinued. The direct replacement is the SAI40AX300. It shares the identical ISO 15552 mounting interface, 40mm bore, 300mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly while adding an upgraded piston seal.
The 40mm bore uses a G1/4 air port. It generates 628 N push and 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, 1130 N push at 0.9 MPa, and a theoretical maximum of 128 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX300
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX300 replacement — usually within 7-8 hours.