This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X310S, 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 SI40X310S
The AirTAC Airtac SI40 Standard Cylinder SI40X310S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 310mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X310S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke310 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X310S
- 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 SI40X310S
The AirTAC SI40X310S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 310mm stroke, delivering 628N push force at 0.5MPa. It features a G1/4 air port and an M12x1.25 rod thread. AirTAC replaced this legacy unit with the SAI40X310S, a direct replacement matching the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI upgrade introduces a refined piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also adds lock and valve variants (SAIL, SAIF, BSAI) absent in the SI line. This -S model includes a piston magnet for legacy CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40X310S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X310S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X310S |
| Bore size | Ø40 mm |
| Stroke | 310 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 SAI40X310S 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 SAI40X310S 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 SI40X310S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×310 | 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 SI40X310S Is Used
Package Diversion
Actuates routing gates on packaging lines, utilizing the 628N push force to smoothly redirect moderate-weight cartons at speed.
Clamp Actuation
Provides 310mm of travel to position and clamp workpieces in CNC machining fixtures, accommodating varied part sizes.
Replacing the Airtac SI40 Standard Cylinder SI40X310S with the SAI40X310S
To replace the SI40X310S, order the SAI40X310S and verify your ISO 15552 mounting interface, G1/4 port thread (PT/G/NPT), and mounting accessories. Because the 310mm stroke exceeds 300mm, add external guides to prevent rod bending and side-load wear. If you need more force, the neighbouring 50mm bore yields 982N push at 0.5MPa; if less is required, the 32mm bore provides 402N. Note that a plain cylinder drifts without live air—the cushion only decelerates. For load holding on air loss, use an external pilot check valve or explore the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X310S
- ✓ 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 SI40X310S FAQ
Yes, the AirTAC SI40X310S is discontinued. The direct replacement is the SAI40X310S. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 310mm stroke, force, G1/4 port, and mounting interface.
The 40mm bore delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa. Operating speed is 30-800 mm/s. It uses a G1/4 port and M12x1.25 rod thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X310S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X310S replacement — usually within 7-8 hours.