This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX120, 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 SI40BX120
The AirTAC Airtac SI40 Standard Cylinder SI40BX120 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 120mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX120, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke120 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX120
- 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 SI40BX120
The AirTAC SI40BX120 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 120mm stroke. Delivering 628 N push force at 0.5 MPa via a G1/4 port, it is replaced by the direct replacement SAI40BX120, which shares the exact mounting interface and dimensions. This non-magnet SKU cannot take a sensor.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. The -B rod is SUS304 stainless steel, and a Viton H seal option raises heat resistance to 150 C.
Airtac SI40 Standard Cylinder SI40BX120 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX120 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX120 |
| Bore size | Ø40 mm |
| Stroke | 120 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 SAI40BX120 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 SAI40BX120 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 SI40BX120
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×120 | 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 SI40BX120 Is Used
Stainless Rod Clamping
Ideal for repetitive clamping tasks where the SUS304 rod resists moisture and corrosion.
Package Diverting
Provides reliable 628 N push force at 0.5 MPa to push or divert light packages on a line.
Replacing the Airtac SI40 Standard Cylinder SI40BX120 with the SAI40BX120
To replace the SI40BX120, order the SAI40BX120, confirming the ISO 15552 interface, 40mm bore, 120mm stroke, G1/4 port, and SUS304 rod. Being a non-magnet version, it cannot accept CS1-B/DS1-B switches. For sizing down, a 32mm bore yields 402 N push at 0.5 MPa; sizing up to 50mm provides 982 N. Note that plain cylinders drift without air, so use a pilot check valve or the SAIL/BSAI lock variants for load holding. At 120mm stroke, side-load risks are low, but always guide the load.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX120
- ✓ 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 SI40BX120 FAQ
Yes, the SI40BX120 is discontinued. The direct replacement is the SAI40BX120, matching the ISO 15552 mounting interface, 40mm bore, 120mm stroke, force, and G1/4 port.
It has a G1/4 port. 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 max of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX120
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX120 replacement — usually within 7-8 hours.