This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X185S, 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 SI40X185S
The AirTAC Airtac SI40 Standard Cylinder SI40X185S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 185mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X185S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke185 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X185S
- 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 SI40X185S
The AirTAC SI40X185S is a discontinued double-acting ISO 15552 profile cylinder featuring a 40 mm bore, 185 mm stroke, and a G1/4 air port. Delivering 628 N push force at 0.5 MPa, it is replaced by the SAI40X185S. This direct successor shares identical mounting, output, and dimensions.
The SAI upgrade uses two Y-shaped one-way piston seals for low start-up pressure and long life. The SAI family also introduces SAIL, SAIF, and BSAI lock variants absent from the SI line. Your -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40X185S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X185S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X185S |
| Bore size | Ø40 mm |
| Stroke | 185 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 SAI40X185S 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 SAI40X185S 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 SI40X185S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×185 | 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 SI40X185S Is Used
Component Clamping
Secures mid-weight machined parts during milling with 628 N of push force at 0.5 MPa.
Package Diverting
Actuates routing gates along packaging lines, utilizing the 185 mm stroke to clear obstructions.
Pallet Stops
Deploys a physical stop block for low-inertia pallets arriving at 30-800 mm/s speeds.
Replacing the Airtac SI40 Standard Cylinder SI40X185S with the SAI40X185S
To replace the SI40X185S, order the SAI40X185S. Confirm the ISO 15552 mounting interface, 40 mm bore, 185 mm stroke, G1/4 port, and M12x1.25 rod thread. Sizing both ways: a 50 mm bore gives 982 N push at 0.5 MPa, while dropping to 32 mm yields 402 N. If you need load holding on air loss, note that plain cylinders drift; use an external pilot check valve or the SAIL/BSAI lock variant. The cushion only decelerates near stroke end. If scaling up stroke beyond 300 mm, add external guides to prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X185S
- ✓ 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 SI40X185S FAQ
Yes, the SI40X185S is discontinued. The direct replacement is the SAI40X185S. It is dimensionally interchangeable per ISO 15552, matching the 40 mm bore, 185 mm stroke, 628 N force, G1/4 port, and mounting fixtures.
It features a G1/4 air port and 16 mm rod. Force output is 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, with a theoretical max of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X185S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X185S replacement — usually within 7-8 hours.