This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X315S, 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 SI40X315S
The AirTAC SI40 Standard Cylinder SI40X315S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 315mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X315S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke315 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X315S
- 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 SI40X315S
The AirTAC SI40X315S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 315mm stroke. It delivers 628 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40X315S, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke, output force, port and mounting accessories.
The SAI replacement introduces an upgraded piston seal featuring two Y-shaped one-way elements for low start-up pressure and extended life. For applications needing load holding, the SAI family adds SAIL and BSAI lock variants the SI lacked. This -S model includes a piston magnet for CS1-B/DS1-B switches.
Airtac SI40 Standard Cylinder SI40X315S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X315S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X315S |
| Bore size | Ø40 mm |
| Stroke | 315 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 SAI40X315S 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 SAI40X315S 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 SI40X315S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×315 | 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 SI40X315S Is Used
Package Diverting
Drives diverter arms on packaging lines where the 628 N push force easily handles routing standard cartons at speed.
Pallet Stops
Acts as a pneumatic stop gate for roller conveyors, using the 315mm stroke to clear the pallet path before release.
Component Ejection
Ejects machined parts from a fixture, benefiting from the adjustable 27mm air cushions to decelerate the rod at stroke end.
Replacing the Airtac SI40 Standard Cylinder SI40X315S with the SAI40X315S
To replace the SI40X315S, order the SAI40X315S and confirm the ISO 15552 mounting interface, 40mm bore, 315mm stroke, G1/4 port (PT/G/NPT thread options) and your mounting accessory. The -S suffix means a magnet is present for CS1-B/DS1-B sensors. For sizing, this bore yields 628 N push at 0.5 MPa; dropping to a 32mm bore gives 402 N, while stepping up to a 50mm bore provides 982 N. Because the 315mm stroke exceeds 300mm, use an external guide to prevent rod bending and side-load damage. 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 → SAI40X315S
- ✓ 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 SI40X315S FAQ
Yes, the AirTAC SI40X315S is discontinued. The direct replacement is the SAI40X315S. It shares the same ISO 15552 mounting interface, 40mm bore, 315mm stroke, output force, G1/4 port and mounting accessories, fitting directly into existing fixtures.
It features a G1/4 air port and provides 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X315S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X315S replacement — usually within 7-8 hours.