This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX350, 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 SI40AX350
The AirTAC Airtac SI40 Standard Cylinder SI40AX350 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 350mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX350, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke350 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX350
- 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 SI40AX350
The AirTAC SI40AX350 is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 350 mm stroke. It delivers 628 N push force at 0.5 MPa through a G1/4 port. The direct replacement is the SAI40AX350, matching the exact ISO 15552 mounting interface, stroke, force, and porting. The SAI upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life.
Because this SKU lacks the -S magnet, it cannot accept position sensors (legacy CS1-B/DS1-B switches require the magnet option). The -A rod code specifies a SUS420J2 stainless piston rod for corrosion resistance over the standard carbon steel. A plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL lock variant.
Airtac SI40 Standard Cylinder SI40AX350 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX350 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX350 |
| Bore size | Ø40 mm |
| Stroke | 350 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 SAI40AX350 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 SAI40AX350 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 SI40AX350
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×350 | 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 SI40AX350 Is Used
Package Diversion
Drives sorting pop-up arms on packaging lines, utilizing the 628 N push force at 0.5 MPa to redirect cartons reliably at conveyor transfers.
Clamp Actuation
Secures mild steel workpieces in CNC machining fixtures, where the SUS420J2 stainless rod provides necessary corrosion resistance against cutting fluids.
Replacing the Airtac SI40 Standard Cylinder SI40AX350 with the SAI40AX350
To replace the SI40AX350, order the SAI40AX350. Verify your ISO 15552 mounting fixture (LB, FA, TC, etc.), the 350 mm stroke, and the G1/4 port. This unit has no -S magnet, so it cannot support sensing; if you need switches, select an SAI40X350S and use current AirTAC sensors. The -A code indicates a SUS420J2 stainless rod; confirm if your environment still requires this or if the default rod suffices. At 0.5 MPa the 40 mm bore yields 628 N push and 528 N pull; if you need less force, step down to a 32 mm bore (402 N push), or step up to 50 mm (982 N push) for more thrust. For load holding on air loss, specify an external rod lock or pilot check valve, or choose the SAIL air-released lock variant. Because the 350 mm stroke is long, prevent rod bending by ensuring external guidance and minimizing side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX350
- ✓ 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 SI40AX350 FAQ
Yes, the AirTAC SI40AX350 is discontinued. The direct replacement is the SAI40AX350. It is dimensionally interchangeable per ISO 15552, retaining the same 40 mm bore, 350 mm stroke, G1/4 port, and mounting interface. The SAI simply upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life.
This 40 mm bore double-acting cylinder features a G1/4 air port and an M12x1.25 rod thread. The thrust output is 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. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX350
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX350 replacement — usually within 7-8 hours.