This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX425, 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 SI40AX425
The AirTAC Airtac SI40 Standard Cylinder SI40AX425 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 425mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX425, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke425 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX425
- 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 SI40AX425
The AirTAC SI40AX425 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 425mm stroke. It delivers 628N push and 528N pull at 0.5MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI40AX425, a direct sharing the exact ISO 15552 mounting interface, bore, stroke, output force, and accessories.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This SKU uses an SUS420J2 stainless rod (option A) for corrosion resistance, but lacks a magnet, so it cannot accept a CS1-B/DS1-B sensor.
Airtac SI40 Standard Cylinder SI40AX425 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX425 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX425 |
| Bore size | Ø40 mm |
| Stroke | 425 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 SAI40AX425 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 SAI40AX425 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 SI40AX425
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×425 | 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 SI40AX425 Is Used
Material Diversion
Actuates routing gates on packaging lines, utilizing the 425mm stroke to clear wide product lanes without collision.
Light Pressing
Applies 628N of push force at 0.5MPa for seating bearings or light assembly tasks, with SUS420J2 rod durability.
Pallet Handling
Extends to push totes or pallets onto accumulation zones, relying on the ISO 15552 mounting for rigid fixture integration.
Replacing the Airtac SI40 Standard Cylinder SI40AX425 with the SAI40AX425
To replace the SI40AX425, order the SAI40AX425. Confirm your ISO 15552 mounting accessory (LB, FA, CA, TC), the G1/4 port thread (PT/G/NPT), and the M12x1.25 rod thread. Because this is a no-S SKU, it cannot take a magnetic switch; if sensing is needed, switch to an SAI40X425S. Sizing both ways: a 50mm bore yields 982N push at 0.5MPa, while a 32mm bore yields 402N. Note the 425mm stroke exceeds 300mm, so use an external guide to prevent rod-bending 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 variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX425
- ✓ 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 SI40AX425 FAQ
Yes, the SI40AX425 is discontinued. The direct replacement is the SAI40AX425. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 425mm stroke, 628N force, G1/4 port, and mounting interface.
This double-acting cylinder has a G1/4 air port. It delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa. Operating speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX425
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX425 replacement — usually within 7-8 hours.