This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX280, 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 SI40BX280
The AirTAC Airtac SI40 Standard Cylinder SI40BX280 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 280mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX280, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke280 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX280
- 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 SI40BX280
The AirTAC SI40BX280 is a discontinued double-acting ISO 15552 profile cylinder featuring a 40mm bore, 280mm stroke, and a SUS304 stainless steel rod. Delivering 628 N push force at 0.5 MPa, it is directly replaced by the SAI40BX280. This direct upgrade matches the G1/4 port, M12x1.25 thread, and ISO 15552 mounting interface for seamless fixture integration.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life. Note this SKU lacks a magnet (-S) and cannot accept a CS1-B/DS1-B sensor. For elevated heat, Viton H seals raise the operating range to 150 C.
Airtac SI40 Standard Cylinder SI40BX280 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX280 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX280 |
| Bore size | Ø40 mm |
| Stroke | 280 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 SAI40BX280 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 SAI40BX280 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 SI40BX280
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×280 | 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 SI40BX280 Is Used
Mid-Stroke Diverting
Provides 280mm of travel to push or divert packages on a line, utilizing adjustable 27mm air cushions to decelerate the payload smoothly.
Replacing the Airtac SI40 Standard Cylinder SI40BX280 with the SAI40BX280
To replace the SI40BX280, order the SAI40BX280, verifying the ISO 15552 mounting interface, 40mm bore, 280mm stroke, G1/4 port (PT/G/NPT), and your specific mounting accessory. Because this stroke is 280mm, ensure adequate guide support to prevent rod-bending and side-load wear. This SKU has no magnet, so position sensing is impossible; if required, switch to an -S equivalent. For sizing, a 32mm bore offers 402 N push at 0.5 MPa, while a 50mm bore provides 982 N. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external pilot check valve or the SAIL/BSAI lock variant for load holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX280
- ✓ 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 SI40BX280 FAQ
Yes, the SI40BX280 is discontinued. The direct replacement is the SAI40BX280. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 280mm stroke, 628 N force, G1/4 port, and mounting interface.
The G1/4 port bore delivers 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. The rod is 16mm with an M12x1.25 thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX280
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX280 replacement — usually within 7-8 hours.