This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X350, 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 SI40X350
The AirTAC Airtac SI40 Standard Cylinder SI40X350 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 SAI40X350, 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 → SAI40X350
- 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 SI40X350
The AirTAC SI40X350 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 via a G1/4 port. The direct replacement is the SAI40X350, matching the exact bore, stroke, force, port, and ISO 15552 mounting interface for existing fixtures.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. Note this non-S SKU lacks a magnet and cannot accept position sensors.
Airtac SI40 Standard Cylinder SI40X350 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X350 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X350 |
| 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 SAI40X350 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 SAI40X350 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 SI40X350
| 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 SI40X350 Is Used
Material Diversion
Actuates routing gates on packaging lines, utilizing the 628 N push force to reliably shift medium-weight cartons between conveyors.
Vertical Pressing
Applies downward clamping pressure for light assembly tasks, safely operating within the 377 N working load margin at 0.5 MPa.
Pallet Handling
Extends 350 mm to push corrugated containers onto exit rollers, requiring external guides to prevent rod bending over the long stroke.
Replacing the Airtac SI40 Standard Cylinder SI40X350 with the SAI40X350
To replace the SI40X350, order the SAI40X350. Confirm the ISO 15552 mounting interface (LB, FA, TC, etc.), the G1/4 port thread (PT/G/NPT), and the M12x1.25 rod thread. Because this is a non-magnet model, it cannot hold a sensor; if sensing is needed, specify an SAI40X350S. For sizing, a 32 mm bore offers 402 N push at 0.5 MPa, while a 50 mm bore provides 982 N. A plain cylinder does not hold load on air loss; use an external pilot check valve or the SAIL/BSAI lock variant. Finally, at 350 mm stroke, prevent rod bending by using an external guide to manage side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X350
- ✓ 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 SI40X350 FAQ
Yes, the SI40X350 is discontinued. The direct replacement is the SAI40X350. It features the same ISO 15552 mounting interface, 40 mm bore, 350 mm stroke, output force, and G1/4 port, fitting directly into existing fixtures.
The 40 mm bore features a G1/4 air port and an M12x1.25 rod thread. 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 force of 128 kgf at 1.0 MPa.
Request a Quote for the SAI40X350
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X350 replacement — usually within 7-8 hours.