This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX270S, 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 SI40BX270S
The AirTAC Airtac SI40 Standard Cylinder SI40BX270S 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 SAI40BX270S, 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 → SAI40BX270S
- 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 SI40BX270S
The AirTAC SI40BX270S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 270 mm stroke. It features a SUS304 stainless steel piston rod for corrosion resistance and a built-in magnet for position sensing. Delivering 628 N push force at 0.5 MPa, its direct replacement is the SAI40BX270S, sharing the exact G1/4 port, M12x1.25 thread, and ISO 15552 mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life. The SAI family also adds SAIL, SAIF, and BSAI lock variants unavailable in the SI line.
Airtac SI40 Standard Cylinder SI40BX270S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX270S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX270S |
| 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 SAI40BX270S 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 SAI40BX270S 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 SI40BX270S
| 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 SI40BX270S Is Used
Bottle Diverting
Routes stainless packaging on washdown lines using the SUS304 rod and 628 N push force at 0.5 MPa.
Carton Stopping
Halts 270 mm stroke cycles at distribution hubs, safely decelerating 32 kg vertical loads via adjustable cushions.
Lab Dispensing
Actuates fluid valves in corrosive environments, relying on the 40 mm bore and Viton H high-temp seal option.
Replacing the Airtac SI40 Standard Cylinder SI40BX270S with the SAI40BX270S
To replace the SI40BX270S, order the SAI40BX270S. It is dimensionally interchangeable per ISO 15552, matching the 40 mm bore, 270 mm stroke, G1/4 port, and mounting accessories. Keep the -S magnet for current AirTAC switches and the -B SUS304 rod. If sizing up, the 50 mm bore offers 982 N push at 0.5 MPa; if sizing down, the 32 mm bore yields 402 N. At 270 mm stroke, use guide rails to prevent rod bending from side loads. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX270S
- ✓ 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 SI40BX270S FAQ
Yes, the SI40BX270S is discontinued. The direct replacement is the SAI40BX270S. It shares the same ISO 15552 mounting interface, 40 mm bore, 270 mm stroke, G1/4 port, and force ratings.
It has a G1/4 port. Force output 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 max of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX270S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX270S replacement — usually within 7-8 hours.