This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX500S, 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 SI40BX500S
The AirTAC Airtac SI40 Standard Cylinder SI40BX500S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 500mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX500S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke500 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX500S
- 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 SI40BX500S
The AirTAC SI40BX500S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore, SUS304 stainless steel rod, and 500 mm stroke. Delivering 628 N push force at 0.5 MPa through a G1/4 port, it is replaced by the SAI40BX500S. This direct upgrade shares identical ISO 15552 mounting dimensions, bore, stroke, and force, fitting existing fixtures perfectly.
The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked. This -S model uses legacy CS1-B/DS1-B sensors; the SAI uses current switches.
Airtac SI40 Standard Cylinder SI40BX500S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX500S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX500S |
| Bore size | Ø40 mm |
| Stroke | 500 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 SAI40BX500S 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 SAI40BX500S 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 SI40BX500S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×500 | 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 SI40BX500S Is Used
Stainless Rod Diverting
Ideal for pushing light packages on packaging lines where the SUS304 rod resists moisture and corrosion.
Vertical Lift Gates
Provides a safe 32 kg vertical lift capacity at 0.5 MPa for raising access gates or light barriers.
Long Stroke Transfers
The 500 mm stroke handles part transfer between machines, provided external guides prevent rod bending.
Replacing the Airtac SI40 Standard Cylinder SI40BX500S with the SAI40BX500S
To replace the SI40BX500S, order the SAI40BX500S. Verify the ISO 15552 mounting interface, 40 mm bore, 500 mm stroke, G1/4 port, and mounting accessory. The -B rod is SUS304 stainless; the -S magnet works with legacy CS1-B/DS1-B switches. For sizing, a 32 mm bore yields 402 N push at 0.5 MPa, while a 50 mm bore yields 982 N. At 500 mm stroke, use external guides to prevent rod bending and side-load wear. A plain cylinder drifts without air; for load holding, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX500S
- ✓ 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 SI40BX500S FAQ
Yes, the SI40BX500S is discontinued. The direct replacement is the SAI40BX500S. It is dimensionally interchangeable per ISO 15552, matching the 40 mm bore, 500 mm stroke, 628 N force, G1/4 port, and mounting interface.
It features a G1/4 port and delivers 628 N push / 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 of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX500S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX500S replacement — usually within 7-8 hours.