This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X85S, 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 SI40X85S
The AirTAC Airtac SI40 Standard Cylinder SI40X85S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 85mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X85S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke85 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X85S
- 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 SI40X85S
The AirTAC SI40X85S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 85mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI40X85S. This direct successor matches the exact ISO 15552 mounting interface, bore, stroke, force, port and accessories.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family adds SAIL, SAIF and BSAI variants the SI lacked. This -S model has a magnet for CS1-B/DS1-B switches; the SAI uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40X85S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X85S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X85S |
| Bore size | Ø40 mm |
| Stroke | 85 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 SAI40X85S 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 SAI40X85S 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 SI40X85S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×85 | 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 SI40X85S Is Used
Component Clamping
Secures mid-weight machined parts during milling or drilling, utilizing the 628N push force at 0.5MPa for rigid workholding.
Package Diverting
Actuates sorting pop-up arms or pushers on packaging lines, with the 85mm stroke providing precise lateral movement.
Pallet Stops
Functions as an indexing stop gate for pallets on roller conveyors, safely holding loads up to the 32kg vertical lift limit.
Replacing the Airtac SI40 Standard Cylinder SI40X85S with the SAI40X85S
To replace this SI40X85S, order the SAI40X85S keeping the identical 40mm bore, 85mm stroke, G1/4 port and ISO 15552 mounting. Confirm your thread option (PT, G or NPT) and mounting accessory (LB, FA, TC, etc.). The -S suffix means a magnet is present for CS1-B/DS1-B sensors. If you need more force, the 50mm bore yields 982N push at 0.5MPa; if less, the 32mm bore gives 402N. A plain cylinder drifts on air loss as the cushion only decelerates, so for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. The SAIF variant integrates a 4M valve if you need self-contained control.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X85S
- ✓ 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 SI40X85S FAQ
Yes, the SI40X85S is discontinued. The direct replacement is the AirTAC SAI40X85S. It features the same ISO 15552 mounting interface, 40mm bore, 85mm stroke, output force, G1/4 port and mounting accessories, fitting directly into existing fixtures.
This double-acting cylinder has a 40mm bore, 16mm rod, M12x1.25 thread, 27mm cushion and operates at 30-800 mm/s. Force ratings are 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa.
Request a Quote for the SAI40X85S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X85S replacement — usually within 7-8 hours.