This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX125, 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 SI40AX125
The AirTAC SI40 Standard Cylinder SI40AX125 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 SAI40AX125, 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 → SAI40AX125
- 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 SI40AX125
The AirTAC SI40AX125 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 125mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI40AX125, matching the exact interface, force, and mounting. This SKU features a SUS420J2 stainless rod (A) but lacks a magnet, so it cannot accept position switches.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and longevity. If you need load holding, note the cushion only decelerates; explore SAIL or BSAI lock variants.
Airtac SI40 Standard Cylinder SI40AX125 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX125 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX125 |
| 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 SAI40AX125 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 SAI40AX125 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 SI40AX125
| 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 SI40AX125 Is Used
Clamping Mechanisms
Ideal for mid-tier clamping tasks on machining fixtures, utilizing the 628N push force at 0.5MPa to secure components firmly during secondary operations.
Package Diverting
Drives 125mm stroke diverting arms on packaging lines to route small to medium cartons, taking advantage of the 30-800mm/s speed range and SUS420J2 stainless rod.
Replacing the Airtac SI40 Standard Cylinder SI40AX125 with the SAI40AX125
To replace the SI40AX125, order the SAI40AX125. Confirm the ISO 15552 mounting interface, 40mm bore, 125mm stroke, G1/4 port (PT/G/NPT), and your specific mounting accessory. Because this SKU lacks the -S magnet, it cannot support sensing; if switches are needed, select an SAI40X125S and use current AirTAC switches. For sizing flexibility, a neighboring 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. At 125mm stroke, rod bending is minimal, but always guide external loads. The cushion only decelerates; for fail-safe load holding, use an external pilot check valve, rod lock, or the SAIL/BSAI variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX125
- ✓ 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 SI40AX125 FAQ
Yes, the AirTAC SI40AX125 is discontinued. The direct replacement is the SAI40AX125. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 125mm stroke, 628N force, G1/4 port, and mounting interface.
This double-acting cylinder uses a G1/4 air port. The thrust ratings are: 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 SAI40AX125
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX125 replacement — usually within 7-8 hours.