This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX280S, 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 SI40BX280S
The AirTAC SI40 Standard Cylinder SI40BX280S 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 SAI40BX280S, 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 → SAI40BX280S
- 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 SI40BX280S
The AirTAC SI40BX280S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore, 280mm stroke, and SUS304 stainless steel rod. It delivers 628 N push and 528 N pull at 0.5 MPa. The direct replacement is the SAI40BX280S, matching the G1/4 port, M12x1.25 thread, and ISO 15552 mounting interface.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The -S magnet works with legacy CS1-B/DS1-B sensors; the SAI uses current AirTAC switches. For high heat, Viton H seals raise the limit to 150 C.
Airtac SI40 Standard Cylinder SI40BX280S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX280S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX280S |
| 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 SAI40BX280S 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 SAI40BX280S 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 SI40BX280S
| 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 SI40BX280S Is Used
Stainless Rod Diverter
Ideal for diverting lightweight packages on a washdown conveyor line, leveraging the 280mm stroke and SUS304 rod for corrosion resistance.
Pneumatic Clamp Arm
Actuates a mid-stroke clamping arm on an assembly fixture, using the adjustable 27mm air cushions to decelerate the load smoothly.
Replacing the Airtac SI40 Standard Cylinder SI40BX280S with the SAI40BX280S
To replace the SI40BX280S, order the SAI40BX280S. Confirm the ISO 15552 mounting interface, 40mm bore, 280mm stroke, G1/4 port, and mounting accessory. The -S magnet enables CS1-B/DS1-B sensors, while the -B rod is SUS304 stainless. At 280mm stroke, use a guide to prevent rod bending and side-load wear. Sizing both ways: a 32mm bore yields 402 N push at 0.5 MPa, while a 50mm bore yields 982 N. A plain cylinder drifts on air loss; for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX280S
- ✓ 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 SI40BX280S FAQ
Yes, the SI40BX280S is discontinued. The direct replacement is the SAI40BX280S. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 280mm stroke, G1/4 port, and mounting interface for a direct fixture fit.
The G1/4 port is fixed by the 40mm bore. Force ratings are: 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 SAI40BX280S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX280S replacement — usually within 7-8 hours.