This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X305S, 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 SI40X305S
The AirTAC Airtac SI40 Standard Cylinder SI40X305S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 305mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X305S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke305 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X305S
- 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 SI40X305S
The AirTAC SI40X305S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 305mm stroke. Delivering 628N push force at 0.5MPa, it is replaced by the SAI40X305S. This direct successor shares the exact G1/4 port, M12x1.25 rod thread and mounting dimensions.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family adds SAIL, SAIF and BSAI lock variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40X305S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X305S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X305S |
| Bore size | Ø40 mm |
| Stroke | 305 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 SAI40X305S 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 SAI40X305S 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 SI40X305S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×305 | 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 SI40X305S Is Used
Component Ejection
Pushes machined parts out of a fixture with 628N force at 0.5MPa, utilizing the 305mm stroke to clear the work area completely.
Package Diverting
Actuates a routing gate along a packaging line, where the G1/4 port and 30-800mm/s speed ensure swift package redirection.
Pallet Positioning
Indexes empty pallets into a loading zone, using the magnetic piston with CS1-B sensors to confirm stroke endpoints.
Replacing the Airtac SI40 Standard Cylinder SI40X305S with the SAI40X305S
To replace the SI40X305S, order the SAI40X305S. Verify the ISO 15552 mounting interface, 305mm stroke, G1/4 port and your -S magnet requirement. If you need more force, the 50mm bore offers 982N push at 0.5MPa; for less, the 32mm bore provides 402N. Because this is a 305mm stroke, use an external guide to prevent rod bending from side loads. A plain cylinder drifts without air; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X305S
- ✓ 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 SI40X305S FAQ
Yes, the SI40X305S is discontinued. The direct replacement is the SAI40X305S. It shares the same ISO 15552 mounting interface, 40mm bore, 305mm stroke, output force, G1/4 port and accessories, fitting directly into existing fixtures.
This double-acting cylinder has a 40mm bore, 16mm rod, M12x1.25 thread, 27mm cushion and G1/4 port. Force ratings are 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa. Speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X305S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X305S replacement — usually within 7-8 hours.