This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX300SH, 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 SI40BX300SH
The AirTAC SI40 Standard Cylinder SI40BX300SH is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 300mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX300SH, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke300 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX300SH
- 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 SI40BX300SH
The AirTAC SI40BX300SH is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 300mm stroke. It delivers 628 N push force at 0.5 MPa through a G1/4 port. This specific configuration includes a SUS304 stainless steel rod (-B) for corrosion resistance, a high-temperature Viton H seal (0-150 C), and a piston magnet (-S) for legacy CS1-B/DS1-B sensors. The direct replacement is the SAI40BX300SH, featuring the same ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life, while adding SAIL, SAIF, and BSAI lock/valve variants absent from the SI line. Because this is a 300mm stroke, external guides are recommended to mitigate rod-bending side loads.
Airtac SI40 Standard Cylinder SI40BX300SH Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX300SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX300SH |
| Bore size | Ø40 mm |
| Stroke | 300 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 SAI40BX300SH 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 SAI40BX300SH 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 SI40BX300SH
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×300 | 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 SI40BX300SH Is Used
Diverting Gates
Actuates routing flaps on packaging lines, where the 628 N push force at 0.5 MPa easily overcomes flap inertia and the SUS304 rod resists humid washdown environments.
High-Temp Ejection
Ejects formed parts near ovens or heat sources, leveraging the Viton H seal rated for 0-150 C to maintain reliable 300mm stroke cycling without degradation.
Replacing the Airtac SI40 Standard Cylinder SI40BX300SH with the SAI40BX300SH
To replace the SI40BX300SH, order the SAI40BX300SH. Verify the ISO 15552 mounting interface, 40mm bore, 300mm stroke, G1/4 port (PT/G/NPT thread), and your specific mounting accessory. Retain the -S magnet for current AirTAC switch compatibility, the -B SUS304 rod, and the -H Viton seal. If more force is needed, the 50mm bore offers 982 N push at 0.5 MPa; if less is required, the 32mm bore provides 402 N. For this 300mm stroke, use external guides to prevent rod-bending side loads. A plain cylinder does not hold load without live air; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX300SH
- ✓ 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 SI40BX300SH FAQ
Yes, the SI40BX300SH is discontinued. The direct replacement is the SAI40BX300SH. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 300mm stroke, 628 N force, G1/4 port, and mounting interface, but features an upgraded two Y-shaped piston seal for lower start-up pressure.
This 40mm bore cylinder uses a G1/4 air port. It generates 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 force of 128 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX300SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX300SH replacement — usually within 7-8 hours.