This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X300N, 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 SI40X300N
The AirTAC SI40 Standard Cylinder SI40X300N is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 300mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X300N, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke300 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X300N
- 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 SI40X300N
The AirTAC SI40X300N is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 300mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40X300N, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and port size. The SAI features an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. The NBR seal supports -20 to +70C, while a Viton H option extends this to 150C. Because this SKU lacks the -S magnet, it cannot accept a CS1-B or DS1-B sensor.
The SAI family also introduces SAIL air-released lock, SAIF built-in 4M valve, and BSAI clamp-lock variants that the original SI line lacked. You can also specify carbon steel, SUS420J2 (A), or SUS304 (B) piston rods.
Airtac SI40 Standard Cylinder SI40X300N Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X300N |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X300N |
| Bore size | Ø40 mm |
| Stroke | 300 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 SAI40X300N 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 SAI40X300N 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 SI40X300N
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×300 | 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 SI40X300N Is Used
Package Diversion
Actuates routing gates on packaging lines, utilizing the 628N push force to smoothly redirect moderate-weight cartons at speeds up to 800 mm/s.
Clamp Actuation
Provides reliable clamping pressure for light machining fixtures, with the 300mm stroke allowing wide clearance for part loading and unloading.
Vertical Lift Stops
Controls material stops on low-friction vertical lift stations, safely moving loads up to 32kg while relying on external guides for stability.
Replacing the Airtac SI40 Standard Cylinder SI40X300N with the SAI40X300N
To replace the discontinued SI40X300N, order the SAI40X300N. Confirm the ISO 15552 mounting interface (LB, FA, FB, CA, CB, TC), the 40mm bore, 300mm stroke, G1/4 port (PT/G/NPT thread options), and M12x1.25 rod thread. Because this SKU lacks the -S magnet, it cannot support position sensing; if you need switches, select an SAI40X300NS and use current AirTAC sensors. Sizing both ways: if you need more force, the 50mm bore offers 982N push at 0.5MPa; if you need less, the 32mm bore provides 402N. For this 300mm stroke, use external guides to prevent rod bending and side-load damage. A plain cylinder drifts on air loss—the 27mm adjustable cushions only decelerate near stroke end. For load holding, use an external pilot check valve, rod lock, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X300N
- ✓ 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 SI40X300N FAQ
Yes, the AirTAC SI40X300N is discontinued. The direct replacement is the SAI40X300N. It is a current-production ISO 15552 cylinder with the same 40mm bore, 300mm stroke, 628N force, G1/4 port, and mounting interface, so it fits existing fixtures directly.
The 40mm bore delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128 kgf at 1.0MPa. Operating speed is 30-800 mm/s. The G1/4 port and M12x1.25 rod thread are fixed by the bore.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X300N
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X300N replacement — usually within 7-8 hours.