This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX260S, 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 SI40BX260S
The AirTAC Airtac SI40 Standard Cylinder SI40BX260S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 260mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX260S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke260 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX260S
- 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 SI40BX260S
The AirTAC SI40BX260S is a discontinued double-acting ISO 15552 profile cylinder featuring a 40mm bore, 260mm stroke, and a SUS304 stainless steel rod. It delivers 628 N push force at 0.5 MPa. The direct replacement is the SAI40BX260S, which retains the exact same G1/4 port, M12x1.25 thread, and mounting interface to fit existing fixtures seamlessly.
The SAI upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure and longer life. This -S model includes a piston magnet for legacy CS1-B/DS1-B sensors, while the SAI accepts current AirTAC switches. A plain cylinder drifts on air loss; for load holding, consider the SAIL lock or BSAI clamp-lock variants.
Airtac SI40 Standard Cylinder SI40BX260S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX260S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX260S |
| Bore size | Ø40 mm |
| Stroke | 260 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 SAI40BX260S 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 SAI40BX260S 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 SI40BX260S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×260 | 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 SI40BX260S Is Used
Stainless Rod Diverter
Ideal for diverting items on a washdown conveyor line, utilizing the 628 N push force and SUS304 rod for corrosion resistance.
Pneumatic Clamping Arm
Actuates a mid-stroke clamping arm in machining fixtures, relying on the 260mm travel and adjustable 27mm cushions.
Replacing the Airtac SI40 Standard Cylinder SI40BX260S with the SAI40BX260S
To replace the SI40BX260S, order the SAI40BX260S. Confirm the ISO 15552 interface, 40mm bore, 260mm stroke, G1/4 port, and mounting accessory. The -B denotes a SUS304 stainless rod for corrosion resistance, and -S indicates the magnet for CS1-B/DS1-B switches. If sizing alternatives, neighbouring bores (32mm or 50mm) change the force output significantly (402 N vs 982 N push at 0.5 MPa). Because the 260mm stroke exceeds 300mm? No, but for any stroke over 300mm, add a guide to prevent rod bending. Note that standard cylinders do not hold load without live air; the cushion only decelerates. For secure holding, use an external pilot check valve or explore the SAIL and BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX260S
- ✓ 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 SI40BX260S FAQ
Yes, the AirTAC SI40BX260S is discontinued. The direct replacement is the SAI40BX260S. It is dimensionally interchangeable per ISO 15552, offering the same 40mm bore, 260mm stroke, G1/4 port, and mounting interface, but features an upgraded piston seal.
The bore is 40mm with a G1/4 air port. The 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 maximum of 128 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX260S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX260S replacement — usually within 7-8 hours.