This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X870S, 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 SI40X870S
The AirTAC Airtac SI40 Standard Cylinder SI40X870S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 870mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X870S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke870 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X870S
- 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 SI40X870S
The AirTAC SI40X870S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 870 mm stroke. It delivers 628 N push force at 0.5 MPa via a G1/4 port. The direct replacement is the SAI40X870S, matching the interface, force, and mounting.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. The SAI family adds SAIL and BSAI lock variants the SI lacked. This -S SKU uses CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40X870S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X870S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X870S |
| Bore size | Ø40 mm |
| Stroke | 870 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 SAI40X870S 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 SAI40X870S 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 SI40X870S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×870 | 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 SI40X870S Is Used
Long-Stroke Diversion
Pushes packages across a 870 mm conveyor lane using the 628 N push force at 0.5 MPa.
Material Extrusion
Feeds aluminium stock through a die over the 870 mm travel with external guides.
Replacing the Airtac SI40 Standard Cylinder SI40X870S with the SAI40X870S
To replace the SI40X870S, order the SAI40X870S. Confirm the ISO 15552 mounting interface, 870 mm stroke, G1/4 port, and your mounting accessory. If downsizing, a 32 mm bore yields 402 N; if upsizing, a 50 mm bore yields 982 N at 0.5 MPa. Because stroke is 870 mm, use an external guide to prevent rod bending. The cushion only decelerates; for load holding on air loss, use a pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X870S
- ✓ 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 SI40X870S FAQ
Yes, the SI40X870S is discontinued. The direct replacement is the SAI40X870S, which shares the same ISO 15552 mounting interface, 40 mm bore, 870 mm stroke, and G1/4 port.
It has a G1/4 port. Force ratings are: 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 max of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X870S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X870S replacement — usually within 7-8 hours.