This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX50, 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 SI40AX50
The AirTAC Airtac SI40 Standard Cylinder SI40AX50 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 SAI40AX50, 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 → SAI40AX50
- 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 SI40AX50
The AirTAC SI40AX50 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 50mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40AX50, a direct upgrade sharing the exact same interface, bore, stroke, force, port and mounting fixtures.
The SAI40AX50 features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. It also adds SAIL, SAIF and BSAI lock variants the SI line lacked. Note this SKU uses a SUS420J2 stainless rod (A) and lacks a magnet, so it cannot take a CS1-B/DS1-B sensor.
Airtac SI40 Standard Cylinder SI40AX50 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX50 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX50 |
| 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 SAI40AX50 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 SAI40AX50 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 SI40AX50
| 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 SI40AX50 Is Used
Clamp Actuation
Provides 628N of push force at 0.5MPa, ideal for securing mid-weight aluminum or steel workpieces during CNC milling.
Package Diverting
Drives a 50mm stroke diverter arm to route small to medium boxes on a sorting line at speeds up to 800mm/s.
Part Ejection
Ejects molded plastic parts from a fixture using the SUS420J2 stainless rod option to resist workshop moisture.
Replacing the Airtac SI40 Standard Cylinder SI40AX50 with the SAI40AX50
To replace the SI40AX50, order the SAI40AX50. Confirm the ISO 15552 mounting interface, 50mm stroke, G1/4 port (PT/G/NPT) and your specific mounting accessory. This SKU has no -S magnet, so it cannot accept a CS1-B/DS1-B sensor; switch to a sensed SAI40X50S if position detection is needed. Sizing both ways: a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for held loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX50
- ✓ 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 SI40AX50 FAQ
Yes, the SI40AX50 is discontinued. The direct replacement is the SAI40AX50. It shares the exact ISO 15552 mounting interface, 40mm bore, 50mm stroke, output force, G1/4 port and accessories, so it drops directly into existing fixtures.
This double-acting cylinder has a G1/4 air port. It delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max force of 128kgf at 1.0MPa.
Request a Quote for the SAI40AX50
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX50 replacement — usually within 7-8 hours.