This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X173S, 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 SI40X173S
The AirTAC Airtac SI40 Standard Cylinder SI40X173S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 173mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X173S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke173 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X173S
- 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 SI40X173S
The AirTAC SI40X173S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 173mm stroke. It delivers 628 N push and 528 N pull at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40X173S, a direct sharing the exact ISO 15552 mounting interface, bore, stroke, force and port.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SI family lacked lock variants, but the SAI line adds SAIL and BSAI clamp-lock options. Note that 173mm is a nonstandard stroke length.
Airtac SI40 Standard Cylinder SI40X173S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X173S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X173S |
| Bore size | Ø40 mm |
| Stroke | 173 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 SAI40X173S 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 SAI40X173S 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 SI40X173S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×173 | 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 SI40X173S Is Used
Clamp Actuation
Provides 628 N of push force at 0.5 MPa, ideal for securing mid-weight workpieces during machining or welding operations.
Package Diversion
Drives 173mm stroke diverters or pushers on packaging lines, moving standard cartons with a 32 kg vertical lift capacity.
Gate Control
Operates access gates or sorting flaps in material handling systems, utilizing the G1/4 port for rapid cycling.
Replacing the Airtac SI40 Standard Cylinder SI40X173S with the SAI40X173S
To replace the SI40X173S, order the SAI40X173S. Confirm the ISO 15552 mounting interface (LB, FA, TC, etc.), the G1/4 port, and the -S magnet for CS1-B/DS1-B legacy sensors (the SAI uses current AirTAC switches). Sizing both ways: a 32mm bore yields 402 N push at 0.5 MPa, while a 50mm bore yields 982 N. Because 173mm is nonstandard, verify tooling clearance. A plain cylinder drifts on air loss as cushions only decelerate; for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. For strokes over 300mm, guide external rods to prevent bending, though 173mm is below that threshold.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X173S
- ✓ 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 SI40X173S FAQ
Yes, the SI40X173S is discontinued. The direct replacement is the SAI40X173S. It shares the identical ISO 15552 mounting interface, 40mm bore, 173mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
This double-acting cylinder features a G1/4 air port and M12x1.25 rod thread. It generates 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 of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X173S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X173S replacement — usually within 7-8 hours.