This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X125, 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 SI40X125
The AirTAC Airtac SI40 Standard Cylinder SI40X125 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 125mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X125, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke125 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X125
- 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 SI40X125
The AirTAC SI40X125 is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 125 mm stroke. It delivers 628 N push force at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI40X125, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI40X125 features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. Note this specific SKU lacks a magnet, so it cannot accept a CS1-B or DS1-B sensor.
Airtac SI40 Standard Cylinder SI40X125 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X125 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X125 |
| Bore size | Ø40 mm |
| Stroke | 125 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 SAI40X125 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 SAI40X125 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 SI40X125
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×125 | 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 SI40X125 Is Used
Component Clamping
Secures mid-weight machined parts during milling or drilling, utilizing the 628 N push force at 0.5 MPa for rigid workholding.
Package Diverting
Actuates sorting gates on packaging lines, where the 125 mm stroke provides sufficient travel to redirect boxes efficiently.
Pallet Stops
Functions as a pneumatic stop pin in low-profile conveyor endpoints, holding goods steady until release for the next station.
Replacing the Airtac SI40 Standard Cylinder SI40X125 with the SAI40X125
To replace the SI40X125, order the SAI40X125. Confirm your ISO 15552 mounting accessory (LB foot, FA/FB flange, or TC trunnion) and the G1/4 port thread (PT, G, or NPT). Because this SKU has no -S magnet, it cannot host a sensor; if sensing is needed, specify an SAI40X125S. For sizing both ways, a neighboring 50 mm bore yields 982 N push at 0.5 MPa, while dropping to a 32 mm bore gives 402 N. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external pilot check valve or the SAIL/BSAI lock variants. At 125 mm stroke, rod bending is minimal, but ensure rigid guidance to prevent side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X125
- ✓ 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 SI40X125 FAQ
Yes, the AirTAC SI40X125 is discontinued. The direct replacement is the SAI40X125. It is dimensionally interchangeable per the ISO 15552 mounting interface, retaining the same 40 mm bore, 125 mm stroke, output force, and G1/4 port, so it fits existing fixtures perfectly.
This 40 mm bore double-acting cylinder uses a G1/4 air port and an 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.
Request a Quote for the SAI40X125
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X125 replacement — usually within 7-8 hours.