This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X185, 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 SI40X185
The AirTAC Airtac SI40 Standard Cylinder SI40X185 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 SAI40X185, 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 → SAI40X185
- 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 SI40X185
The AirTAC SI40X185 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 185mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI40X185. This direct successor matches the exact interface, bore, stroke, force and mounting fixtures.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. It also introduces SAIL, SAIF and BSAI lock variants the SI lacked. Note this no-S SKU cannot take a sensor.
Airtac SI40 Standard Cylinder SI40X185 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X185 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X185 |
| 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 SAI40X185 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 SAI40X185 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 SI40X185
| 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 SI40X185 Is Used
Package Diversion
Actuates routing gates on packaging lines where 628N push force at 0.5MPa easily redirects standard cartons.
Clamp Actuation
Provides reliable holding pressure for mid-sized machining fixtures, utilizing its 528N pull force at 0.5MPa.
Replacing the Airtac SI40 Standard Cylinder SI40X185 with the SAI40X185
To replace the SI40X185, order the SAI40X185 direct: verify the ISO 15552 mounting interface, 185mm stroke, M12x1.25 rod thread, G1/4 port and your mounting accessory. Because this is a no-S SKU, it cannot accept a CS1-B/DS1-B sensor; if sensing is needed, order the SAI40X185S. For sizing, the neighbouring 32mm bore yields 402N push at 0.5MPa, while the 50mm bore yields 982N. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock or pilot check valve for load holding, or specify the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X185
- ✓ 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 SI40X185 FAQ
Yes, the AirTAC SI40X185 is discontinued. The direct replacement is the SAI40X185. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 185mm stroke, G1/4 port and mounting interface.
This double-acting cylinder has a G1/4 air port. It generates 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max force of 128kgf at 1.0MPa.
Request a Quote for the SAI40X185
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X185 replacement — usually within 7-8 hours.