This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX120S, 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 SI40BX120S
The AirTAC Airtac SI40 Standard Cylinder SI40BX120S 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 SAI40BX120S, 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 → SAI40BX120S
- 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 SI40BX120S
The AirTAC SI40BX120S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore, 120mm stroke, and a SUS304 stainless piston rod. It delivers 628 N push and 528 N pull at 0.5 MPa through a G1/4 port. The direct replacement is the SAI40BX120S, matching the interface, force, and mounting exactly.
The SAI upgrade features 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.
Airtac SI40 Standard Cylinder SI40BX120S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX120S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX120S |
| 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 SAI40BX120S 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 SAI40BX120S 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 SI40BX120S
| 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 SI40BX120S Is Used
Stainless Rod Clamping
Ideal for packaging machinery requiring corrosion resistance, using the SUS304 rod to clamp components with 628 N of push force.
Material Diversion
Deploys a 120mm stroke gate to redirect small to medium items on a processing line, benefiting from the adjustable air cushions.
Replacing the Airtac SI40 Standard Cylinder SI40BX120S with the SAI40BX120S
To replace the SI40BX120S, order the SAI40BX120S. Confirm the ISO 15552 mounting interface, 120mm stroke, G1/4 port (PT/G/NPT), and mounting accessory. The -B rod is SUS304 stainless, and the -S magnet supports CS1-B/DS1-B switches. Output is 628 N push at 0.5 MPa; sizing down to a 32mm bore yields 402 N, while a 50mm bore gives 982 N. Air cushions only decelerate; for load holding on air loss, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. At 120mm stroke, rod bending is low, but for strokes over 300mm add a guide to prevent side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX120S
- ✓ 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 SI40BX120S FAQ
Yes, the SI40BX120S is discontinued. The direct replacement is the SAI40BX120S. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 120mm stroke, G1/4 port, and mounting interface.
This double-acting cylinder features a G1/4 air port and an M12x1.25 rod thread. It provides 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 theoretical max of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX120S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX120S replacement — usually within 7-8 hours.