This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X350N, 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 SI40X350N
The AirTAC Airtac SI40 Standard Cylinder SI40X350N 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 SAI40X350N, 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 → SAI40X350N
- 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 SI40X350N
The AirTAC SI40X350N is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 350mm stroke. It delivers 628N push and 528N pull at 0.5MPa through a G1/4 port. The direct replacement is the SAI40X350N, matching the exact bore, stroke, force, port and ISO 15552 mounting interface for seamless fixture integration.
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 sensor, though legacy SI types used CS1-B/DS1-B switches. The NBR seal suits -20 to +70C.
Airtac SI40 Standard Cylinder SI40X350N Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X350N |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X350N |
| 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 SAI40X350N 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 SAI40X350N 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 SI40X350N
| 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 SI40X350N Is Used
Vertical Lift Stops
Raises lightweight material stops up to 32kg in distribution hubs, relying on the G1/4 port for rapid actuation.
Clamp Actuation
Positions mid-force clamping arms on machining fixtures, taking advantage of the 628N push force at 0.5MPa.
Replacing the Airtac SI40 Standard Cylinder SI40X350N with the SAI40X350N
To replace the SI40X350N, order the SAI40X350N, confirming the ISO 15552 mounting interface, 40mm bore, 350mm stroke, G1/4 port (PT/G/NPT thread options) and mounting accessory. Because this SKU has no magnet, it cannot accept a sensor. For force sizing, a 32mm bore offers 402N push at 0.5MPa, while a 50mm bore gives 982N. At 350mm stroke, use external guides to prevent rod bending and side-load wear. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X350N
- ✓ 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 SI40X350N FAQ
Yes, the SI40X350N is discontinued. The direct replacement is the SAI40X350N. It features the same ISO 15552 mounting interface, 40mm bore, 350mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
This double-acting cylinder has a G1/4 port. 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. Speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X350N
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X350N replacement — usually within 7-8 hours.