This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X690S, 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 SI40X690S
The AirTAC SI40 Standard Cylinder SI40X690S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 690mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X690S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke690 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X690S
- 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 SI40X690S
The AirTAC SI40X690S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 690 mm stroke. Delivering 628 N push force at 0.5 MPa via a G1/4 port, it is directly replaced by the SAI40X690S. This direct upgrade shares the exact ISO 15552 mounting interface, bore, stroke, and force, fitting existing fixtures perfectly.
The SAI successor improves longevity with two Y-shaped one-way piston seals for lower start-up pressure. For this 690 mm stroke, external guides are advised to prevent rod bending. The -S magnet supports legacy CS1-B/DS1-B sensors, while the SAI family adds SAIL lock and SAIF valve variants.
Airtac SI40 Standard Cylinder SI40X690S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X690S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X690S |
| Bore size | Ø40 mm |
| Stroke | 690 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 SAI40X690S 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 SAI40X690S 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 SI40X690S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×690 | 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 SI40X690S Is Used
Long-Stroke Diversion
Pushes packages across a 690 mm transfer gap with 628 N at 0.5 MPa, requiring external guides to absorb side-impact without bending the rod.
Component Ejection
Ejects machined parts from a press over a 690 mm distance, relying on the 27 mm adjustable air cushions to decelerate the 16 mm rod smoothly.
Replacing the Airtac SI40 Standard Cylinder SI40X690S with the SAI40X690S
To replace the SI40X690S, order the SAI40X690S. Confirm the ISO 15552 mounting interface, 40 mm bore, 690 mm stroke, G1/4 port (PT/G/NPT), and mounting accessory. The -S denotes a piston magnet for CS1-B/DS1-B switches; the SAI uses current AirTAC switches. For sizing, neighbouring bores are 32 mm (402 N push @0.5 MPa) and 50 mm (982 N push @0.5 MPa). At 690 mm, add external guides to prevent rod bending under side loads. A plain cylinder drifts without live air; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X690S
- ✓ 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 SI40X690S FAQ
Yes, the AirTAC SI40X690S is discontinued. The direct replacement is the SAI40X690S. It shares the identical ISO 15552 mounting interface, 40 mm bore, 690 mm stroke, output force, and G1/4 port, fitting directly into your existing fixtures.
This double-acting cylinder features a G1/4 air port and a 16 mm rod. The thrust ratings are: 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 maximum of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X690S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X690S replacement — usually within 7-8 hours.