This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X35STC, 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 SI40X35STC
The AirTAC Airtac SI40 Standard Cylinder SI40X35STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 35mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X35STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke35 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X35STC
- 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 SI40X35STC
The AirTAC SI40X35STC is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 35mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40X35STC, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke and force.
The SAI replacement 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 variants the SI line lacked. The -S magnet works with CS1-B/DS1-B sensors, and rod materials include SUS420J2 or SUS304.
Airtac SI40 Standard Cylinder SI40X35STC Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X35STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X35STC |
| Bore size | Ø40 mm |
| Stroke | 35 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 SAI40X35STC 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 SAI40X35STC 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 SI40X35STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×35 | 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 SI40X35STC Is Used
Short-Stroke Clamping
Ideal for holding light machined components during milling or drilling, utilizing the 628N push force and 35mm stroke for rapid, repeatable actuation.
Package Diverting
Provides reliable lateral pushing force at transfer stations. The TC trunnion mount handles the angular loads of short-stroke routing gates perfectly.
Part Ejection
Deploys quickly to push finished parts out of testing jigs.
Replacing the Airtac SI40 Standard Cylinder SI40X35STC with the SAI40X35STC
To replace the SI40X35STC, order the SAI40X35STC and verify the TC trunnion mount, G1/4 port, M12x1.25 rod thread and the -S magnet for CS1-B/DS1-B switches. The SAI drops into existing ISO 15552 fixtures seamlessly. Sizing both ways: if you need less force, a 32mm bore yields 402N at 0.5MPa; for more power, a 50mm bore gives 982N. Note that a plain cylinder drifts on air loss—the cushion only decelerates. For load holding, specify the SAIL lock or BSAI clamp-lock variant, or use an external pilot check valve. If exploring higher temperatures, select the Viton H seal option for 0-150C operation.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X35STC
- ✓ 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 SI40X35STC FAQ
Yes, the AirTAC SI40X35STC is discontinued. The direct replacement is the SAI40X35STC. It shares the identical ISO 15552 mounting interface, 40mm bore, 35mm stroke, 628N force and G1/4 port, fitting existing fixtures without modification.
The 40mm bore double-acting cylinder provides 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. Operating speed is 30-800 mm/s. It uses a G1/4 port and M12x1.25 rod thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X35STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X35STC replacement — usually within 7-8 hours.