This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX25, 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 SI40BX25
The AirTAC Airtac SI40 Standard Cylinder SI40BX25 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 25mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX25, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke25 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX25
- 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 SI40BX25
The AirTAC SI40BX25 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 25mm stroke, delivering 628 N push force at 0.5 MPa through its G1/4 port. The direct replacement is the SAI40BX25, matching the bore, stroke, force, port, and ISO 15552 mounting interface for existing fixtures.
The SAI upgrade features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This SKU uses a SUS304 stainless steel rod (B option) and lacks a magnet, meaning it cannot take a CS1-B/DS1-B sensor.
Airtac SI40 Standard Cylinder SI40BX25 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX25 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX25 |
| Bore size | Ø40 mm |
| Stroke | 25 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 SAI40BX25 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 SAI40BX25 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 SI40BX25
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×25 | 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 SI40BX25 Is Used
Short-Stroke Clamping
Ideal for securely clamping small machined parts in CNC fixtures using its 628 N push force over a compact 25mm travel distance.
Stainless Rod Ejection
The SUS304 piston rod excels in ejecting corrosive or washed components from molds, providing reliable resistance in damp environments.
Package Diverting
Delivers rapid 30-800 mm/s actuation for diverting light packages on conveyor lines where a short, snappy motion is required.
Replacing the Airtac SI40 Standard Cylinder SI40BX25 with the SAI40BX25
To replace the SI40BX25, order the SAI40BX25. Verify the ISO 15552 mounting interface, the G1/4 port, and the M12x1.25 rod thread. Because this SKU lacks a magnet (-S), it cannot accept legacy CS1-B/DS1-B sensors; if position detection is needed, select a magnet-equipped SAI model. This 40mm bore yields 628 N push at 0.5 MPa; if more force is needed, the 50mm bore offers 982 N. If less force is needed, the 32mm bore provides 402 N. A plain cylinder does not hold load on air loss—the cushion only decelerates—so for load holding use an external pilot check valve or the SAIL/BSAI lock variants. The 25mm stroke is short, so side-load risks are minimal, but ensure the SUS304 rod is specified for corrosive environments.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX25
- ✓ 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 SI40BX25 FAQ
Yes, the AirTAC SI40BX25 is discontinued. The direct replacement is the SAI40BX25. It is dimensionally interchangeable per ISO 15552, keeping the same 40mm bore, 25mm stroke, G1/4 port, and mounting interface.
This double-acting cylinder features a G1/4 air port and an M12x1.25 rod thread. It delivers 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 max force of 128 kgf at 1.0 MPa.
Request a Quote for the SAI40BX25
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX25 replacement — usually within 7-8 hours.