This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX5S, 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 SI40BX5S
The AirTAC Airtac SI40 Standard Cylinder SI40BX5S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 5mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX5S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke5 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX5S
- 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 SI40BX5S
The AirTAC SI40BX5S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore, 5mm stroke, and a SUS304 stainless steel rod. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI40BX5S. This direct upgrade shares the same interface, force, and mounting, but adds an upgraded piston seal using two Y-shaped one-way elements for low start-up pressure and long life. The -S magnet works with legacy CS1-B/DS1-B sensors.
The SAI family also introduces SAIL, SAIF, and BSAI lock variants absent in the SI line. Note that a plain cylinder drifts on air loss; the cushion only decelerates, so use an external rod lock for holding.
Airtac SI40 Standard Cylinder SI40BX5S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX5S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX5S |
| Bore size | Ø40 mm |
| Stroke | 5 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 SAI40BX5S 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 SAI40BX5S 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 SI40BX5S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×5 | 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 SI40BX5S Is Used
Short-Stroke Clamping
Ideal for compact clamping tasks in machining fixtures where a 5mm stroke securely holds components without excessive travel.
Stainless Rod Ejection
The SUS304 rod option excels in ejecting small parts or delicate electronic components in mildly corrosive or cleanroom-adjacent environments.
Valve Actuation
Provides reliable short-throw linear motion to pilot or toggle small process valves in tight machinery envelopes where a 40mm bore delivers sufficient thrust.
Replacing the Airtac SI40 Standard Cylinder SI40BX5S with the SAI40BX5S
To replace the SI40BX5S, order the SAI40BX5S. Confirm the ISO 15552 mounting interface, 40mm bore, 5mm stroke, G1/4 port, and the -S magnet for current AirTAC switches. The SUS304 rod provides corrosion resistance versus standard carbon steel. If you need more force, the neighbouring 50mm bore offers 982N push at 0.5MPa; if less is required, the 32mm bore provides 402N. For load holding, remember this cylinder drifts without live air—the cushion only decelerates—so specify a SAIL lock variant or an external pilot check valve. The SAIF variant integrates a 4M valve if space is tight.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX5S
- ✓ 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 SI40BX5S FAQ
Yes, the SI40BX5S is discontinued. The direct replacement is the SAI40BX5S. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 5mm stroke, G1/4 port, and mounting interface to fit existing fixtures directly.
It features a G1/4 port and provides 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, and 1130N push at 0.9MPa. The theoretical maximum force is 128kgf at 1.0MPa. It operates at 30-800mm/s with a 27mm adjustable air cushion.
Request a Quote for the SAI40BX5S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX5S replacement — usually within 7-8 hours.