This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X50, 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 SI40X50
The AirTAC Airtac SI40 Standard Cylinder SI40X50 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 SAI40X50, 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 → SAI40X50
- 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 SI40X50
The AirTAC SI40X50 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 50mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the direct replacement SAI40X50. The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life, while the ISO 15552 mounting interface and output force remain identical.
This non-magnet SKU cannot take a sensor, unlike the legacy CS1-B/DS1-B switches used on -S models. The SAI family also introduces SAIL, SAIF and BSAI lock variants absent from the SI line.
Airtac SI40 Standard Cylinder SI40X50 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X50 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X50 |
| 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 SAI40X50 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 SAI40X50 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 SI40X50
| 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 SI40X50 Is Used
Compact Part Ejection
Ideal for pushing finished parts from a machining center using its 628N push force and short 50mm stroke.
Package Routing
Actuates diverter arms on a packaging line where a 32kg safe vertical lift margin handles light goods reliably.
Clamp Actuation
Provides repeatable clamping pressure for small aluminum fixtures in automated assembly cells.
Replacing the Airtac SI40 Standard Cylinder SI40X50 with the SAI40X50
To replace the SI40X50, order the SAI40X50 keeping the exact 40mm bore, 50mm stroke, G1/4 port and ISO 15552 mounting. Confirm your thread option (PT/G/NPT) and mounting accessory (LB, FA, TC, etc.). This SKU lacks a magnet (-S), so it cannot accept a position sensor; if sensing is needed, switch to an SAI40X50S. For higher force, the neighbouring 50mm bore provides 982N push at 0.5MPa. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X50
- ✓ 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 SI40X50 FAQ
Yes, the AirTAC SI40X50 is discontinued. The direct replacement is the SAI40X50. It features the same ISO 15552 mounting interface, 40mm bore, 50mm stroke, 628N force and G1/4 port, fitting existing fixtures perfectly.
The 40mm bore uses a G1/4 port and M12x1.25 rod thread. It delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a maximum theoretical force of 128kgf at 1.0MPa.
Request a Quote for the SAI40X50
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X50 replacement — usually within 7-8 hours.