This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX40S, 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 SI40BX40S
The AirTAC Airtac SI40 Standard Cylinder SI40BX40S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 40mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX40S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke40 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX40S
- 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 SI40BX40S
The AirTAC SI40BX40S is a discontinued double-acting ISO 15552 profile cylinder featuring a 40mm bore, 40mm stroke, and a SUS304 stainless steel rod. It delivers 628 N push force at 0.5 MPa. The direct replacement is the SAI40BX40S, matching the bore, stroke, force, G1/4 port, and ISO 15552 mounting interface exactly.
The SAI upgrade introduces 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, while the SAI family adds SAIL, SAIF, and BSAI lock variants.
Airtac SI40 Standard Cylinder SI40BX40S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX40S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX40S |
| Bore size | Ø40 mm |
| Stroke | 40 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 SAI40BX40S 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 SAI40BX40S 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 SI40BX40S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×40 | 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 SI40BX40S Is Used
Stainless Rod Clamping
Ideal for short-stroke clamping in washdown environments where the SUS304 rod resists corrosion.
Package Diverting
Provides reliable 40mm diverting strokes on packaging lines, utilizing the 628 N push force.
Compact Ejection
Ejects small machined parts from fixtures using a short 40mm stroke and adjustable cushions.
Replacing the Airtac SI40 Standard Cylinder SI40BX40S with the SAI40BX40S
To replace the SI40BX40S, order the SAI40BX40S. Verify the ISO 15552 mounting interface, 40mm stroke, G1/4 port, and the -S magnet. The -B code specifies a SUS304 stainless rod for corrosion resistance; default is carbon steel. Sizing both ways: a 32mm bore yields 402 N push at 0.5 MPa, while a 50mm bore yields 982 N. This plain cylinder does not hold load without live air; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX40S
- ✓ 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 SI40BX40S FAQ
Yes, the SI40BX40S is discontinued. The direct replacement is the SAI40BX40S. It is dimensionally interchangeable per the ISO 15552 mounting interface, retaining the same 40mm bore, 40mm stroke, 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, at 0.9 MPa it is 1130 N, and the theoretical max is 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX40S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX40S replacement — usually within 7-8 hours.