This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X185STC, 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 SI40X185STC
The AirTAC Airtac SI40 Standard Cylinder SI40X185STC 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 SAI40X185STC, 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 → SAI40X185STC
- 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 SI40X185STC
The AirTAC SI40X185STC is a discontinued double-acting ISO 15552 profile cylinder featuring a 40mm bore, 185mm stroke, and a TC trunnion mount. Delivering 628N push force at 0.5MPa, it uses a G1/4 port and a 16mm rod. AirTAC replaced this legacy unit with the SAI40X185STC, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, and force.
The SAI replacement introduces an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. The SAI family also adds SAIL, SAIF, and BSAI lock variants absent in the SI line.
Airtac SI40 Standard Cylinder SI40X185STC Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X185STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X185STC |
| 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 SAI40X185STC 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 SAI40X185STC 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 SI40X185STC
| 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 SI40X185STC Is Used
Package Diversion
Actuates routing gates on packaging lines where 628N push force easily deflects standard cartons.
Clamp Actuation
Secures medium workpieces during machining, using the 185mm stroke to clear the tooling area fully.
Replacing the Airtac SI40 Standard Cylinder SI40X185STC with the SAI40X185STC
To replace the SI40X185STC, order the SAI40X185STC. It drops directly into existing fixtures via the identical ISO 15552 TC trunnion mounting interface, matching the 40mm bore, 185mm stroke, 16mm rod, M12x1.25 thread, and G1/4 port. Retain the -S magnet for position sensing, though note the legacy CS1-B/DS1-B switches are superseded by current AirTAC sensors on the SAI. If you need more force, the 50mm bore yields 982N push at 0.5MPa; if less is required, the 32mm bore provides 402N. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding consider an external pilot check valve or the SAIL/BSAI lock variants. At 185mm stroke, side-load risks are low, but ensure smooth rod alignment to prevent premature seal wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X185STC
- ✓ 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 SI40X185STC FAQ
Yes, the SI40X185STC is discontinued. The direct replacement is the SAI40X185STC. It shares the identical ISO 15552 mounting interface, 40mm bore, 185mm stroke, G1/4 port, and output force, fitting your existing fixtures perfectly.
This 40mm bore cylinder features a G1/4 air port. It delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical maximum force of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X185STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X185STC replacement — usually within 7-8 hours.