This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X340S, 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 SI40X340S
The AirTAC SI40 Standard Cylinder SI40X340S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 340mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X340S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke340 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X340S
- 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 SI40X340S
The AirTAC SI40X340S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 340 mm stroke. It delivers 628 N push and 528 N pull at 0.5 MPa, utilizing a G1/4 port and M12x1.25 rod thread. The direct replacement is the SAI40X340S, sharing the same ISO 15552 mounting interface, bore, stroke, output force, and porting.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. For applications needing load holding on air loss, the SAI family introduces SAIL and BSAI lock variants the SI lacked.
Airtac SI40 Standard Cylinder SI40X340S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X340S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X340S |
| Bore size | Ø40 mm |
| Stroke | 340 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 SAI40X340S 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 SAI40X340S 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 SI40X340S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×340 | 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 SI40X340S Is Used
Pneumatic Ejector
Ejects machined parts from fixtures, benefiting from the adjustable 27 mm air cushions to decelerate the 16 mm rod at stroke ends.
Replacing the Airtac SI40 Standard Cylinder SI40X340S with the SAI40X340S
To replace the SI40X340S, order the SAI40X340S, confirming the ISO 15552 mounting interface, 40 mm bore, 340 mm stroke, G1/4 port (PT/G/NPT), and the -S magnet for CS1-B/DS1-B switches. When sizing, consider neighbouring bores: a 32 mm bore offers 402 N push, while a 50 mm bore provides 982 N at 0.5 MPa. For this 340 mm stroke, use external guides to prevent rod bending and side-load wear. A plain cylinder does not hold load without live air; the cushion only decelerates. For secure holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X340S
- ✓ 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 SI40X340S FAQ
Yes, the SI40X340S is discontinued. The direct replacement is the SAI40X340S. It shares the same ISO 15552 mounting interface, 40 mm bore, 340 mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
The 40 mm bore cylinder features a G1/4 port and M12x1.25 rod thread. It delivers 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 max of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X340S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X340S replacement — usually within 7-8 hours.