This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X235S, 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 SI40X235S
The AirTAC SI40 Standard Cylinder SI40X235S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 235mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X235S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke235 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X235S
- 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 SI40X235S
The AirTAC SI40X235S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 235 mm stroke. It delivers 628 N push force at 0.5 MPa through a G1/4 port. The direct replacement is the SAI40X235S, retaining identical ISO 15552 mounting dimensions, bore, stroke, output force, and porting to fit existing fixtures.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The SI -S suffix indicates a piston magnet for legacy CS1-B/DS1-B sensors, whereas the SAI uses current AirTAC switches. For high heat, Viton H seals raise the temperature limit to 150 C.
Airtac SI40 Standard Cylinder SI40X235S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X235S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X235S |
| Bore size | Ø40 mm |
| Stroke | 235 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 SAI40X235S 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 SAI40X235S 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 SI40X235S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×235 | 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 SI40X235S Is Used
Package Diversion
Actuates routing gates on packaging lines, utilizing the 628 N push force to smoothly redirect cartons at 30-800 mm/s.
Clamp Actuation
Drives mid-force clamping mechanisms for machining fixtures, relying on the 16 mm rod and 27 mm cushions for stable stops.
Replacing the Airtac SI40 Standard Cylinder SI40X235S with the SAI40X235S
To replace the SI40X235S, order the SAI40X235S and confirm the ISO 15552 interface, 40 mm bore, 235 mm stroke, G1/4 port, and mounting accessory. The -S magnet carries over. At 0.5 MPa it pushes 628 N; sizing down to a 32 mm bore yields 402 N, while a 50 mm bore provides 982 N. For loads needing 235 mm of travel, use guide rails to prevent rod bending and side-load wear. A plain SAI does not hold load without live air; the cushion only decelerates. For fail-safe holding, specify the SAIL or BSAI lock variant, or add an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X235S
- ✓ 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 SI40X235S FAQ
Yes, the SI40X235S is discontinued. The direct replacement is the SAI40X235S. It shares the same ISO 15552 mounting interface, 40 mm bore, 235 mm stroke, force, and G1/4 port, fitting existing setups perfectly.
The 40 mm bore uses a G1/4 port. It generates 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. Speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X235S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X235S replacement — usually within 7-8 hours.