This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX70S, 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 SI40AX70S
The AirTAC Airtac SI40 Standard Cylinder SI40AX70S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 70mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX70S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke70 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX70S
- 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 SI40AX70S
The AirTAC SI40AX70S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 70 mm stroke. It delivers 628 N push and 528 N pull at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI40AX70S, a direct upgrade sharing the exact ISO 15552 mounting interface, M12x1.25 rod thread and 27 mm cushions.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This SI40AX70S variant uses a SUS420J2 stainless rod and a piston magnet for legacy CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40AX70S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX70S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX70S |
| Bore size | Ø40 mm |
| Stroke | 70 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 SAI40AX70S 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 SAI40AX70S 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 SI40AX70S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×70 | 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 SI40AX70S Is Used
Component Clamping
Ideal for securing mid-weight machined parts during milling or drilling, utilizing the 628 N push force at 0.5 MPa.
Package Diverting
Drives short-stroke routing gates on assembly lines, benefiting from the 30-800 mm/s speed range and 70 mm travel.
Replacing the Airtac SI40 Standard Cylinder SI40AX70S with the SAI40AX70S
To replace the SI40AX70S, order the SAI40AX70S. Verify your ISO 15552 mounting fixtures, the G1/4 air port, and the M12x1.25 rod thread. Because this SKU includes the -S magnet, it supports CS1-B/DS1-B switches, while the SAI uses current AirTAC sensors. For sizing flexibility, a neighbouring 32 mm bore offers less force, while a 50 mm bore gives 982 N push at 0.5 MPa. Note that a plain cylinder drifts on air loss; the cushions only decelerate. For load holding, use an external pilot check valve or explore the SAIL lock and BSAI clamp-lock variants. The 70 mm stroke keeps side-load risks low, but always guide the load.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX70S
- ✓ 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 SI40AX70S FAQ
Yes, the SI40AX70S is discontinued. The direct replacement is the SAI40AX70S. It shares the identical ISO 15552 mounting interface, 40 mm bore, 70 mm stroke, G1/4 port, and force ratings, fitting existing fixtures perfectly.
The 40 mm bore uses a G1/4 air port. Force output is 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX70S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX70S replacement — usually within 7-8 hours.