This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X400, 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 SI40X400
The AirTAC SI40 Standard Cylinder SI40X400 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 SAI40X400, 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 → SAI40X400
- 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 SI40X400
The AirTAC SI40X400 is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 400 mm stroke. It delivers 628 N push force at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI40X400, a direct sharing the same interface, bore, stroke, force, port and mounting.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This SKU lacks a magnet (-S), so it cannot take a CS1-B/DS1-B sensor. For high heat, Viton H seals raise the limit to 150 C.
Airtac SI40 Standard Cylinder SI40X400 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X400 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X400 |
| 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 SAI40X400 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 SAI40X400 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 SI40X400
| 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 SI40X400 Is Used
Carton Diverting
Pushes packages at 30-800 mm/s on packaging lines, using the 628 N thrust to redirect items without stalling.
Pallet Gate Control
Actuates safety gates or light stops, where the long 400 mm stroke clears wide pallet paths efficiently.
Replacing the Airtac SI40 Standard Cylinder SI40X400 with the SAI40X400
To replace the SI40X400, order the SAI40X400. Confirm the ISO 15552 mounting interface (LB, FA, TC, etc.), the 400 mm stroke, and the G1/4 port (PT/G/NPT). Because this SKU has no magnet, it cannot accept position sensors; order a -S variant if switches are needed. At 0.5 MPa it pushes 628 N; sizing down, a 32 mm bore yields 402 N, while sizing up, a 50 mm bore yields 982 N. The 400 mm stroke demands external guides to prevent rod bending under side loads. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock, a pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X400
- ✓ 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 SI40X400 FAQ
Yes, the AirTAC SI40X400 is discontinued. The direct replacement is the SAI40X400. It is dimensionally interchangeable per ISO 15552, retaining the same 40 mm bore, 400 mm stroke, 628 N force, G1/4 port, and mounting fixtures.
This double-acting cylinder 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 maximum of 128 kgf at 1.0 MPa.
Request a Quote for the SAI40X400
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X400 replacement — usually within 7-8 hours.