This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX240S, 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 SI40BX240S
The AirTAC Airtac SI40 Standard Cylinder SI40BX240S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 240mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX240S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke240 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX240S
- 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 SI40BX240S
The AirTAC SI40BX240S is a discontinued double-acting ISO 15552 profile cylinder featuring a SUS304 stainless piston rod and a 240 mm stroke. Delivering 628 N push force at 0.5 MPa through a G1/4 port, it is replaced by the SAI40BX240S. This direct successor matches the exact bore, stroke, force, port and ISO 15552 mounting interface of the legacy unit.
The SAI upgrade introduces an advanced two Y-shaped one-way piston seal for low start-up pressure and extended life. For applications needing load holding, the SAI family adds SAIL and BSAI lock variants absent in the SI line.
Airtac SI40 Standard Cylinder SI40BX240S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX240S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX240S |
| Bore size | Ø40 mm |
| Stroke | 240 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 SAI40BX240S 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 SAI40BX240S 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 SI40BX240S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×240 | 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 SI40BX240S Is Used
Stainless Rod Diverting
Ideal for diverting items on packaging lines where the SUS304 rod resists moisture and the 628 N thrust handles lateral pusher loads.
Compact Assembly Ejection
Ejects machined parts from fixtures using the 879 N push force at 0.7 MPa, fitting neatly into existing ISO 15552 tooling.
Replacing the Airtac SI40 Standard Cylinder SI40BX240S with the SAI40BX240S
To replace the SI40BX240S, order the SAI40BX240S, matching the 40 mm bore, 240 mm stroke, G1/4 port, and ISO 15552 mounting interface. The -B rod is SUS304 stainless steel and the -S suffix means it has a piston magnet for CS1-B/DS1-B switches; the SAI replacement uses current AirTAC switches. For sizing, a 50 mm bore offers 982 N push at 0.5 MPa, while a 32 mm bore provides 402 N. A plain cylinder drifts on air loss as the cushion only decelerates; use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant to hold loads. At 240 mm stroke, guide the load to prevent rod bending and side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX240S
- ✓ 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 SI40BX240S FAQ
Yes, the SI40BX240S is discontinued. The direct replacement is the SAI40BX240S. It shares the identical ISO 15552 mounting interface, 40 mm bore, 240 mm stroke, G1/4 port, and output force, fitting existing fixtures perfectly.
The bore is 40 mm with a G1/4 air port. The thrust 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. It operates at 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX240S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX240S replacement — usually within 7-8 hours.