This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X820STC, 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 SI40X820STC
The AirTAC SI40 Standard Cylinder SI40X820STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 820mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X820STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke820 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X820STC
- 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 SI40X820STC
The AirTAC SI40X820STC is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 820mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is directly replaced by the SAI40X820STC. This direct successor shares the exact ISO 15552 mounting interface, TC trunnion, and M12x1.25 rod thread.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The original SI line lacked SAIL, SAIF, and BSAI variants now available. Note that 820mm strokes require external guides to prevent rod bending.
Airtac SI40 Standard Cylinder SI40X820STC Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X820STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X820STC |
| Bore size | Ø40 mm |
| Stroke | 820 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 SAI40X820STC 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 SAI40X820STC 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 SI40X820STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×820 | 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 SI40X820STC Is Used
Long-Stroke Diversion
Pushes packages across a 820mm conveyor lane using the 628N push force at 0.5MPa, guided by external rails to prevent rod bending.
TC Trunnion Positioning
Pivots a heavy fixture arm using the ISO 15552 TC trunnion mount, relying on the 27mm adjustable cushion to decelerate the swing.
Replacing the Airtac SI40 Standard Cylinder SI40X820STC with the SAI40X820STC
To replace the SI40X820STC, order the SAI40X820STC, confirming the ISO 15552 TC trunnion mount, 820mm stroke, G1/4 port, and the -S magnet for CS1-B/DS1-B switches (the SAI uses current AirTAC switches). Sizing both ways: a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. At 820mm, add external guides to prevent side-load and rod-bending. A plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X820STC
- ✓ 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 SI40X820STC FAQ
Yes, the SI40X820STC is discontinued. The direct replacement is the SAI40X820STC. It shares the same ISO 15552 mounting interface, 40mm bore, 820mm stroke, G1/4 port, and output force, fitting existing fixtures perfectly.
The 40mm bore features a G1/4 air port and M12x1.25 rod thread. 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. Operating speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X820STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X820STC replacement — usually within 7-8 hours.