This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX850S, 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 SI40AX850S
The AirTAC Airtac SI40 Standard Cylinder SI40AX850S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 850mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX850S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke850 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX850S
- 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 SI40AX850S
The AirTAC SI40AX850S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 850mm stroke. Delivering 628 N push force at 0.5 MPa, it features a SUS420J2 stainless rod, a G1/4 port, and a piston magnet for legacy CS1-B/DS1-B sensors. The direct replacement is the SAI40AX850S, which shares the same interface, force, and port.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants lacking in the SI line.
Airtac SI40 Standard Cylinder SI40AX850S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX850S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX850S |
| Bore size | Ø40 mm |
| Stroke | 850 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 SAI40AX850S 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 SAI40AX850S 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 SI40AX850S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×850 | 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 SI40AX850S Is Used
Storage Retrieval
Extracts totes from deep shelving units where the G1/4 port and ISO 15552 mounts fit existing frames.
Replacing the Airtac SI40 Standard Cylinder SI40AX850S with the SAI40AX850S
To replace the SI40AX850S, order the SAI40AX850S, confirming the ISO 15552 mounting interface, 40mm bore, 850mm stroke, G1/4 port, and the -S magnet for current AirTAC switches. If you need to size up or down, adjacent bores (32mm or 50mm) offer different forces, with the 50mm bore yielding 982 N push at 0.5 MPa. Because this is an 850mm stroke, use an external guide to prevent rod-bending and side-load damage. Note that a plain cylinder does not hold load on air loss; for load holding, use an external rod lock, a pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX850S
- ✓ 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 SI40AX850S FAQ
Yes, the SI40AX850S is discontinued. The direct replacement is the SAI40AX850S. It is dimensionally interchangeable per ISO 15552, keeping the same 40mm bore, 850mm stroke, 628 N force, G1/4 port, and mounting interface.
The G1/4 port bore delivers a push force of 628 N and a pull force of 528 N at 0.5 MPa. At 0.7 MPa push is 879 N, at 0.9 MPa it is 1130 N, and the theoretical max is 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX850S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX850S replacement — usually within 7-8 hours.