This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X512S, 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 SI40X512S
The AirTAC SI40 Standard Cylinder SI40X512S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 512mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X512S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke512 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X512S
- 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 SI40X512S
The AirTAC SI40X512S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 512mm stroke. Delivering 628N push at 0.5MPa through a G1/4 port, it is replaced by the SAI40X512S. This direct successor matches the exact ISO 15552 mounting interface, bore, output force and accessories. The SAI features an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. It also adds variants the SI lacked, like the SAIL air-released lock and BSAI clamp-lock.
The -S suffix denotes a piston magnet for legacy CS1-B/DS1-B sensors. Note that plain cylinders drift on air loss; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL lock variant. The 512mm stroke requires external guides to prevent rod bending.
Airtac SI40 Standard Cylinder SI40X512S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X512S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X512S |
| Bore size | Ø40 mm |
| Stroke | 512 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 SAI40X512S 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 SAI40X512S 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 SI40X512S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×512 | 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 SI40X512S Is Used
Package Diverting
Drives diverting arms on packaging lines where the 528N pull force at 0.5MPa easily redirects standard cartons.
Vertical Lowering
Lowers light fixtures with a 32kg vertical lift capacity, requiring external guides for the 512mm stroke.
Pallet Handling
Positions pallet stops and gates, utilizing the G1/4 port and ISO 15552 mounting for seamless fixture integration.
Replacing the Airtac SI40 Standard Cylinder SI40X512S with the SAI40X512S
To replace the SI40X512S, order the SAI40X512S. Confirm the ISO 15552 mounting interface, 40mm bore, 512mm stroke, G1/4 port (PT/G/NPT thread options) and your mounting accessory. The -S magnet allows current AirTAC switches to replace legacy CS1-B/DS1-B sensors. Sizing both ways: this 40mm bore gives 628N push at 0.5MPa (879N at 0.7MPa); if undersized, the 50mm bore offers 982N. A plain cylinder does not hold load without live air, so for drop protection use an external rod lock or pilot check valve, or step up to the SAIL/BSAI lock variants. Because 512mm exceeds 300mm, add external guides to manage side-load and prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X512S
- ✓ 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 SI40X512S FAQ
Yes, the SI40X512S is discontinued. The direct replacement is the SAI40X512S. It shares the same ISO 15552 mounting interface, 40mm bore, 512mm stroke, output force, G1/4 port and accessories, fitting existing fixtures perfectly.
The 40mm bore uses a G1/4 air port and M12x1.25 rod thread. It delivers 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X512S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X512S replacement — usually within 7-8 hours.