This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX50S, 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 SI40BX50S
The AirTAC Airtac SI40 Standard Cylinder SI40BX50S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 50mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX50S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke50 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX50S
- 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 SI40BX50S
The AirTAC SI40BX50S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore, 50 mm stroke, and a SUS304 stainless steel piston rod. Delivering 628 N push force at 0.5 MPa, it is replaced by the SAI40BX50S. This direct upgrade matches the G1/4 port, M12x1.25 thread, and ISO 15552 mounting interface.
The SAI features an upgraded piston seal with two Y-shaped elements for low start-up pressure and long life. The -S magnet supports legacy CS1-B/DS1-B sensors, while SAIL lock and SAIF valve variants expand options.
Airtac SI40 Standard Cylinder SI40BX50S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX50S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX50S |
| Bore size | Ø40 mm |
| Stroke | 50 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 SAI40BX50S 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 SAI40BX50S 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 SI40BX50S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×50 | 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 SI40BX50S Is Used
Stainless Rod Clamping
Ideal for moderate-duty clamping tasks where the SUS304 rod resists moisture, providing 628 N of reliable push force at 0.5 MPa.
Short-Stroke Diverting
The 50 mm stroke excels at diverting light packages on automated lines, operating smoothly at speeds between 30 and 800 mm/s.
Replacing the Airtac SI40 Standard Cylinder SI40BX50S with the SAI40BX50S
To replace the SI40BX50S, order the SAI40BX50S. Verify the ISO 15552 mounting interface, 50 mm stroke, G1/4 port (PT/G/NPT), and the -S magnet for CS1-B/DS1-B switches. The -B rod is SUS304 stainless steel. Sizing both ways: the 32 mm bore yields 402 N push at 0.5 MPa, while the 50 mm bore yields 982 N. For load holding, note that a plain cylinder drifts on air loss as the cushion only decelerates; use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX50S
- ✓ 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 SI40BX50S FAQ
Yes, the SI40BX50S is discontinued. The direct replacement is the SAI40BX50S, which shares the same ISO 15552 mounting interface, 40 mm bore, 50 mm stroke, 628 N force, and G1/4 port.
The G1/4 port bore delivers a push of 628 N and pull of 528 N at 0.5 MPa. At 0.7 MPa push is 879 N, and 1130 N at 0.9 MPa. The theoretical maximum force is 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX50S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX50S replacement — usually within 7-8 hours.