This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX850, 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 SI40BX850
The AirTAC Airtac SI40 Standard Cylinder SI40BX850 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 850mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX850, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke850 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX850
- 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 SI40BX850
The AirTAC SI40BX850 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 850mm stroke. Delivering 628N push force at 0.5MPa through a G1/4 port, it is replaced by the SAI40BX850. This direct upgrade shares the exact interface, force, and mounting.
The SAI features an upgraded piston seal with two Y-shaped elements for low start-up pressure. This SKU uses a SUS304 stainless rod (-B) and lacks a magnet, so it cannot take sensors. For high heat, Viton H seals raise temps to 150C.
Airtac SI40 Standard Cylinder SI40BX850 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX850 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX850 |
| Bore size | Ø40 mm |
| Stroke | 850 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 SAI40BX850 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 SAI40BX850 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 SI40BX850
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×850 | 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 SI40BX850 Is Used
Long-Stroke Diversion
Handles 850mm routing of packages on packaging lines, using the SUS304 rod for washdown corrosion resistance.
OEM Machinery
Direct replacement SAI40BX850 fits existing ISO 15552 fixtures seamlessly without altering the G1/4 pneumatic layout.
Replacing the Airtac SI40 Standard Cylinder SI40BX850 with the SAI40BX850
To replace the SI40BX850, order the SAI40BX850. Confirm the ISO 15552 mounting interface, 40mm bore, 850mm stroke, G1/4 port, and SUS304 rod. This non-magnet SKU cannot accept CS1-B/DS1-B switches. At 0.5MPa it yields 628N push and 528N pull; neighboring bores offer 402N (32mm) or 982N (50mm). The 850mm stroke requires external guides to prevent rod bending. The cushion only decelerates; for load holding on air loss, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX850
- ✓ 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 SI40BX850 FAQ
Yes, the SI40BX850 is discontinued. The direct replacement is the SAI40BX850, which shares the same ISO 15552 mounting interface, 40mm bore, 850mm stroke, force, G1/4 port, and SUS304 rod.
It features a G1/4 port and provides 628N push / 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX850
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX850 replacement — usually within 7-8 hours.