This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX275, 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 SI40BX275
The AirTAC Airtac SI40 Standard Cylinder SI40BX275 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 275mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX275, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke275 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX275
- 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 SI40BX275
The AirTAC SI40BX275 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore, 275mm stroke, and SUS304 stainless steel rod. Delivering 628 N push force at 0.5 MPa via a G1/4 port, it is replaced by the SAI40BX275. This direct successor shares identical ISO 15552 mounting dimensions, bore, stroke, output force, and port size, fitting existing fixtures perfectly.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and long life. Because this specific SKU lacks a magnet (-S), it cannot accept a CS1-B or DS1-B sensor.
Airtac SI40 Standard Cylinder SI40BX275 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX275 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX275 |
| Bore size | Ø40 mm |
| Stroke | 275 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 SAI40BX275 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 SAI40BX275 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 SI40BX275
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×275 | 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 SI40BX275 Is Used
Stainless Rod Actuation
Ideal for packaging equipment requiring corrosion resistance, utilizing the SUS304 rod to push 628 N loads reliably.
Mid-Stroke Diversion
Handles 275mm travel to divert products on a line, benefiting from the 30-800 mm/s speed range and adjustable cushions.
Replacing the Airtac SI40 Standard Cylinder SI40BX275 with the SAI40BX275
To replace the SI40BX275, order the SAI40BX275. Verify the ISO 15552 mounting interface, 40mm bore, 275mm stroke, G1/4 port, and SUS304 rod material. Since this SKU has no magnet, it cannot support position sensing; add the -S suffix if switches are needed. For load holding, note that a standard cylinder drifts without live air—the cushion only decelerates. Use an external pilot check valve or the SAIL/BSAI lock variant for secure holds. At 275mm stroke, guide side-loads to prevent rod bending. If downsizing, a 32mm bore yields 402 N push at 0.5 MPa; if upsizing, a 50mm bore provides 982 N.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX275
- ✓ 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 SI40BX275 FAQ
Yes, the AirTAC SI40BX275 is discontinued. The direct replacement is the SAI40BX275. It shares the same ISO 15552 mounting interface, 40mm bore, 275mm stroke, output force, and G1/4 port, fitting directly into existing fixtures.
This double-acting cylinder features a G1/4 air port and delivers 628 N push / 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 SAI40BX275
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX275 replacement — usually within 7-8 hours.