This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX950S, 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 SI40BX950S
The AirTAC Airtac SI40 Standard Cylinder SI40BX950S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 950mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX950S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke950 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX950S
- 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 SI40BX950S
The AirTAC SI40BX950S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 950mm stroke. It delivers 628 N push force at 0.5 MPa through a G1/4 port. The direct replacement is the SAI40BX950S, which matches the original bore, stroke, force, port and ISO 15552 mounting interface exactly.
This SAI upgrade features a revised piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. The -B code specifies a SUS304 stainless steel piston rod for corrosion resistance, and the -S magnet works with legacy CS1-B/DS1-B switches.
Airtac SI40 Standard Cylinder SI40BX950S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX950S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX950S |
| Bore size | Ø40 mm |
| Stroke | 950 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 SAI40BX950S 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 SAI40BX950S 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 SI40BX950S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×950 | 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 SI40BX950S Is Used
Long-Stroke Diversion
Pushes packages across transfer lines using the 950mm stroke, relying on the 628 N push force at 0.5 MPa to overcome friction.
Stainless Rod Ejection
Ejects parts in humid washdown environments using the SUS304 piston rod option to resist corrosion over the long travel distance.
Replacing the Airtac SI40 Standard Cylinder SI40BX950S with the SAI40BX950S
To replace the SI40BX950S, order the SAI40BX950S and confirm the ISO 15552 mounting interface, 40mm bore, 950mm stroke, G1/4 port, and SUS304 rod option. If you need less force, a 32mm bore provides 402 N push at 0.5 MPa; for more force, a 50mm bore yields 982 N. Because this is a 950mm stroke, use external guides to prevent rod bending and side-load damage. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock or pilot check valve for load holding, or select the SAIL or BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX950S
- ✓ 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 SI40BX950S FAQ
Yes, the SI40BX950S is discontinued. The direct replacement is the SAI40BX950S. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 950mm stroke, G1/4 port, and mounting interface.
The G1/4 port supplies a push force of 628 N and pull of 528 N at 0.5 MPa. At 0.7 MPa push is 879 N, at 0.9 MPa it is 1130 N, and the theoretical max is 128 kgf at 1.0 MPa. Speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX950S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX950S replacement — usually within 7-8 hours.