This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX400SH, 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 SI40BX400SH
The AirTAC Airtac SI40 Standard Cylinder SI40BX400SH is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 400mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX400SH, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke400 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX400SH
- 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 SI40BX400SH
The AirTAC SI40BX400SH is a discontinued double-acting ISO 15552 profile cylinder featuring a 40mm bore, 400mm stroke, SUS304 stainless steel rod, and Viton H high-temperature seals. Delivering 628 N push force at 0.5 MPa via a G1/4 port, its direct replacement is the SAI40BX400SH. This current-production SAI model preserves the exact ISO 15552 mounting interface, bore, stroke, and output force, fitting existing fixtures perfectly while introducing an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life.
The SAI family also introduces variants the legacy SI line lacked, such as the SAIL air-released lock, SAIF built-in valve, and BSAI clamp-lock. This -S magnet model supports legacy CS1-B/DS1-B sensors, while the SAI replacement uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40BX400SH Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX400SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX400SH |
| Bore size | Ø40 mm |
| Stroke | 400 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 SAI40BX400SH 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 SAI40BX400SH 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 SI40BX400SH
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×400 | 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 SI40BX400SH Is Used
High-Temp Diverting
Actuating diverters or gates on hot material conveyors where the Viton H seal and SUS304 rod withstand elevated ambient temperatures up to 150 C.
Corrosive Fluid Handling
Pilot-operating valves in washdown or chemically exposed environments, utilizing the SUS304 stainless piston rod to prevent rust and degradation.
Extended Reach Ejection
Pushing parts out of machinery over a 400mm span, requiring external guide rails to prevent rod bending during the long stroke ejection cycle.
Replacing the Airtac SI40 Standard Cylinder SI40BX400SH with the SAI40BX400SH
To replace the discontinued SI40BX400SH, order the SAI40BX400SH. Confirm the ISO 15552 mounting interface (LB, FA, CA, TC, etc.), the 40mm bore, the 400mm stroke, and the G1/4 port. Retain the -B SUS304 stainless rod for corrosion resistance, the -H Viton seal for 0-150 C high-temperature environments, and the -S magnet for position sensing. When sizing both ways, a 32mm bore offers 402 N push at 0.5 MPa, while a 50mm bore provides 982 N. Note that a plain cylinder does not hold load on air loss; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. Because the 400mm stroke exceeds 300mm, use external guides to prevent rod bending and side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX400SH
- ✓ 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 SI40BX400SH FAQ
Yes, the SI40BX400SH is discontinued. The direct replacement is the SAI40BX400SH. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 400mm stroke, 628 N force, G1/4 port, and mounting interface, so it fits existing fixtures.
The G1/4 port feeds a 16mm piston rod delivering 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. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX400SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX400SH replacement — usually within 7-8 hours.