This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X300SN, 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 SI40X300SN
The AirTAC Airtac SI40 Standard Cylinder SI40X300SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 300mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X300SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke300 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X300SN
- 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 SI40X300SN
The AirTAC SI40X300SN is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 300mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI40X300SN. This direct upgrade shares the exact ISO 15552 mounting interface, bore, stroke, force, port and mounting accessories, fitting existing fixtures perfectly.
The SAI upgrade 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 lacked. With the -S magnet, the legacy CS1-B/DS1-B sensors fit; the -N NBR seal supports -20 to +70C.
Airtac SI40 Standard Cylinder SI40X300SN Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X300SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X300SN |
| Bore size | Ø40 mm |
| Stroke | 300 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 SAI40X300SN 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 SAI40X300SN 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 SI40X300SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×300 | 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 SI40X300SN Is Used
Material Diversion
Actuates sorting gates on packaging lines, using the 628N push force at 0.5 MPa to deflect cartons reliably.
Pallet Handling
Extends 300 mm to push lightweight tote bins off roller conveyors, utilizing the adjustable air cushions for smooth stops.
Replacing the Airtac SI40 Standard Cylinder SI40X300SN with the SAI40X300SN
To replace the SI40X300SN, order the SAI40X300SN direct: confirm the ISO 15552 interface, 40mm bore, 300mm stroke, G1/4 port (PT/G/NPT thread options), NBR seal, magnet (-S for CS1-B/DS1-B switches), and mounting accessory. Size both ways: a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. Note that a plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. At 300mm stroke, prevent rod bending by using an external guide to manage side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X300SN
- ✓ 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 SI40X300SN FAQ
Yes, the SI40X300SN is discontinued. The direct replacement is the SAI40X300SN. It shares the same ISO 15552 mounting interface, 40mm bore, 300mm stroke, output force, G1/4 port, and mounting accessories, fitting existing fixtures directly.
The 40mm bore uses a G1/4 air port. Force ratings are: 628N push and 528N pull at 0.5 MPa, 879N push at 0.7 MPa, 1130N 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 SAI40X300SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X300SN replacement — usually within 7-8 hours.