This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX270, 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 SI40BX270
The AirTAC Airtac SI40 Standard Cylinder SI40BX270 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 270mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX270, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke270 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX270
- 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 SI40BX270
The AirTAC SI40BX270 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore, 270mm stroke, SUS304 stainless piston rod, and G1/4 port. It delivers 628N push force at 0.5MPa. The direct replacement is the SAI40BX270, sharing the exact ISO 15552 mounting interface, bore, stroke, output force, and porting.
Because this SKU lacks the -S magnet, it cannot accept a sensor. The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure. For load holding, note that standard cylinders drift without live air; use an external rod lock or SAIL/BSAI variant.
Airtac SI40 Standard Cylinder SI40BX270 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX270 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX270 |
| Bore size | Ø40 mm |
| Stroke | 270 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 SAI40BX270 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 SAI40BX270 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 SI40BX270
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×270 | 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 SI40BX270 Is Used
Stainless Rod Diverters
Ideal for pushing lightweight packages on packaging lines where the SUS304 rod resists moisture and the 628N force easily redirects items at 270mm stroke.
Lab Equipment Actuation
Suitable for laboratory automation requiring a corrosion-resistant piston rod, providing precise 270mm movement without needing magnetic position sensing.
Replacing the Airtac SI40 Standard Cylinder SI40BX270 with the SAI40BX270
To replace the discontinued SI40BX270, order the SAI40BX270. Confirm the ISO 15552 mounting fixture, 40mm bore, 270mm stroke, G1/4 port (PT/G/NPT thread), and your specific mounting accessory (LB, FA, TC, etc.). This unit has a SUS304 (-B) rod for corrosion resistance and no magnet, so it cannot use CS1-B/DS1-B sensors. For sizing, a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. At 270mm stroke, ensure side-load alignment to prevent rod bending, utilizing guide rails if necessary. The air cushion only decelerates; it does not hold loads on air loss—install a pilot check valve or explore the SAIL lock or SAIF self-valve variants if needed.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX270
- ✓ 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 SI40BX270 FAQ
Yes, the SI40BX270 is discontinued. The direct replacement is the SAI40BX270. It shares the identical ISO 15552 mounting interface, 40mm bore, 270mm stroke, output force, and G1/4 port, fitting directly into your existing fixtures.
This double-acting cylinder has a G1/4 air port. The thrust ratings are: 628N push and 528N pull at 0.5 MPa, 879N push at 0.7 MPa, 1130N push at 0.9 MPa, and a theoretical max of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX270
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX270 replacement — usually within 7-8 hours.