This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX225S, 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 SI40BX225S
The AirTAC Airtac SI40 Standard Cylinder SI40BX225S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 225mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX225S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke225 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX225S
- 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 SI40BX225S
The AirTAC SI40BX225S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 225 mm stroke. It features a SUS304 stainless piston rod (-B) for corrosion resistance, a built-in magnet (-S), and delivers 628 N push force at 0.5 MPa via its G1/4 port. AirTAC replaced this legacy unit with the SAI40BX225S, a direct sharing the exact ISO 15552 mounting interface, bore, stroke, output force, and porting.
The SAI upgrade introduces a refined piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also expands functionality with SAIL, SAIF, and BSAI lock or valve variants absent in the original SI line.
Airtac SI40 Standard Cylinder SI40BX225S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX225S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX225S |
| Bore size | Ø40 mm |
| Stroke | 225 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 SAI40BX225S 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 SAI40BX225S 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 SI40BX225S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×225 | 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 SI40BX225S Is Used
Diverting Gate
Actuates routing flaps on packaging lines, using the 225 mm stroke to shift products between parallel belts reliably.
Carton Stopper
Extends across roller conveyors to halt cardboard cartons, utilizing the SUS304 rod for humid washdown environments.
Replacing the Airtac SI40 Standard Cylinder SI40BX225S with the SAI40BX225S
To replace the SI40BX225S, order the SAI40BX225S and confirm the ISO 15552 mounting interface, 40 mm bore, 225 mm stroke, G1/4 port, and your specific mounting accessory. Retain the -S magnet for current AirTAC switches and the -B SUS304 rod option. If you need more force, the neighboring 50 mm bore yields 982 N push at 0.5 MPa; if less is required, the 32 mm bore provides 402 N. Because this is a 225 mm stroke, ensure adequate guidance to prevent rod bending under side loads. A plain cylinder drifts on air loss, so for load holding consider an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX225S
- ✓ 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 SI40BX225S FAQ
Yes, the SI40BX225S is discontinued. The direct replacement is the SAI40BX225S. It shares the identical ISO 15552 mounting interface, 40 mm bore, 225 mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
This 40 mm bore cylinder features 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX225S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX225S replacement — usually within 7-8 hours.