This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX210S, 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 SI40AX210S
The AirTAC Airtac SI40 Standard Cylinder SI40AX210S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 210mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX210S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke210 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX210S
- 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 SI40AX210S
The AirTAC SI40AX210S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore, 210mm stroke, and a SUS420J2 stainless steel rod. Delivering 628 N push force at 0.5 MPa, it is replaced by the SAI40AX210S. This direct successor shares the exact interface, G1/4 port, and M12x1.25 rod thread. The SAI features an upgraded piston seal with two Y-shaped elements for lower start-up pressure and longer life. It also adds SAIL, SAIF, and BSAI lock variants the SI lacked.
The built-in magnet supports CS1-B/DS1-B sensors. Note that air cushions only decelerate; for load holding on air loss, use an external rod lock or pilot check valve.
Airtac SI40 Standard Cylinder SI40AX210S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX210S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX210S |
| Bore size | Ø40 mm |
| Stroke | 210 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 SAI40AX210S 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 SAI40AX210S 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 SI40AX210S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×210 | 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 SI40AX210S Is Used
Stainless Rod Actuation
The SUS420J2 rod excels in mildly corrosive parts ejection and clamping tasks where standard carbon steel would pit.
Mid-Stroke Diverting
Using 628 N of push force at 0.5 MPa, this 210mm stroke unit reliably pushes light pallets off a transfer line.
Replacing the Airtac SI40 Standard Cylinder SI40AX210S with the SAI40AX210S
To replace the SI40AX210S, order the SAI40AX210S. Confirm the ISO 15552 mounting interface, G1/4 port, M12x1.25 thread, and the -S magnet for legacy CS1-B/DS1-B switches (the SAI uses current AirTAC switches). Size both ways: the 32mm bore yields 402 N push at 0.5 MPa, while the 50mm bore yields 982 N. For this 210mm stroke, ensure guide alignment to prevent rod bending. A plain cylinder drifts without air; for load holding, specify a SAIL lock, BSAI clamp-lock, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX210S
- ✓ 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 SI40AX210S FAQ
Yes, the SI40AX210S is discontinued. The direct replacement is the SAI40AX210S. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 210mm stroke, force, G1/4 port, and mounting fixtures.
This double-acting cylinder has a G1/4 air port. It delivers 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 SAI40AX210S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX210S replacement — usually within 7-8 hours.