This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X400STC, 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 SI40X400STC
The AirTAC SI40 Standard Cylinder SI40X400STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 400mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X400STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke400 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X400STC
- 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 SI40X400STC
The AirTAC SI40X400STC is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 400mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the direct replacement SAI40X400STC. This upgrade retains the exact TC trunnion mounting, M12x1.25 rod thread, and 27mm cushions, but introduces an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life.
The SAI family also adds SAIL, SAIF, and BSAI lock variants missing from the SI line. Your -S code denotes a piston magnet for legacy CS1-B/DS1-B sensors, though the SAI replacement uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40X400STC Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X400STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X400STC |
| Bore size | Ø40 mm |
| Stroke | 400 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 SAI40X400STC 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 SAI40X400STC 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 SI40X400STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×400 | 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 SI40X400STC Is Used
Carton Diverting
Pushes packages at 30-800 mm/s on packaging lines, utilizing the 400mm stroke to clear the conveyor lane completely.
Light Pressing
Applies up to 879N of push force at 0.7MPa for seating light components or holding assemblies firmly in place.
Pallet Loading
Extends 400mm to push standardized totes or product layers onto pallets, guided by the TC trunnion mount.
Replacing the Airtac SI40 Standard Cylinder SI40X400STC with the SAI40X400STC
To replace this SI40X400STC, order the SAI40X400STC. Confirm the ISO 15552 TC trunnion mount, 40mm bore, 400mm stroke, G1/4 port, and the -S magnet. If you need more force, the neighbouring 50mm bore yields 982N push at 0.5MPa; if less is acceptable, the 32mm bore provides 402N. Because this is a 400mm stroke, use an external guide to prevent rod bending and side-load wear. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock or pilot check valve for load holding, or switch to the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X400STC
- ✓ 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 SI40X400STC FAQ
Yes, the AirTAC SI40X400STC is discontinued. The direct replacement is the SAI40X400STC. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 400mm stroke, G1/4 port, TC mount, and output force.
The 40mm bore provides 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128 kgf at 1.0MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X400STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X400STC replacement — usually within 7-8 hours.