This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX155S, 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 SI40BX155S
The AirTAC Airtac SI40 Standard Cylinder SI40BX155S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 155mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX155S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke155 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX155S
- 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 SI40BX155S
The AirTAC SI40BX155S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore, 155mm stroke, and a SUS304 stainless steel rod. Delivering 628N push force at 0.5MPa, it is replaced by the SAI40BX155S. This direct upgrade matches the G1/4 port, M12x1.25 thread, and mounting interface exactly.
The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure. The -S magnet works with CS1-B/DS1-B sensors, while the SAI family adds SAIL lock and SAIF valve variants.
Airtac SI40 Standard Cylinder SI40BX155S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX155S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX155S |
| Bore size | Ø40 mm |
| Stroke | 155 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 SAI40BX155S 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 SAI40BX155S 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 SI40BX155S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×155 | 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 SI40BX155S Is Used
Stainless Rod Actuation
Leverages the SUS304 rod for corrosion resistance in washdown or mildly chemical manufacturing environments.
Mid-Force Diversion
Provides 628N push at 0.5MPa to reliably divert packages on a 155mm stroke without overloading the mechanism.
Replacing the Airtac SI40 Standard Cylinder SI40BX155S with the SAI40BX155S
To replace the SI40BX155S, order the SAI40BX155S. Confirm the ISO 15552 interface, 155mm stroke, G1/4 port, and mounting accessory. The -B rod is SUS304 stainless; the -S magnet supports legacy CS1-B/DS1-B switches (SAI uses current AirTAC switches). For sizing, a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. The cushion only decelerates; it does not hold load 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 → SAI40BX155S
- ✓ 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 SI40BX155S FAQ
Yes, the SI40BX155S is discontinued. The direct replacement is the SAI40BX155S, which shares the same ISO 15552 mounting interface, 40mm bore, 155mm stroke, G1/4 port, and output force.
It features a 40mm bore, 16mm rod, G1/4 port, M12x1.25 thread, and 27mm cushion. Speed is 30-800mm/s. Force ratings: push 628N and pull 528N at 0.5MPa, push 879N at 0.7MPa, and a max theoretical force of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX155S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX155S replacement — usually within 7-8 hours.