This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X1650S, 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 SI40X1650S
The AirTAC Airtac SI40 Standard Cylinder SI40X1650S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 1650mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X1650S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke1650 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X1650S
- 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 SI40X1650S
The AirTAC SI40X1650S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 1650 mm stroke. It delivers 628 N push force at 0.5 MPa via a G1/4 port. Because 1650 mm exceeds the 1200 mm standard maximum for this bore, it is a non-standard, made-to-order length. The direct replacement is the SAI40X1650S, matching the ISO 15552 mounting interface, stroke, output force and accessories.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL, SAIF and BSAI lock variants the SI lacked. This -S model has a piston magnet for CS1-B/DS1-B switches; the SAI uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40X1650S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X1650S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X1650S |
| Bore size | Ø40 mm |
| Stroke | 1650 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 SAI40X1650S 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 SAI40X1650S 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 SI40X1650S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×1650 | 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 SI40X1650S Is Used
Extended Reach Push
Drives materials across wide gantry spans where a 1650 mm stroke is required to bridge machine sections.
High Bay Diverting
Actuates diverter arms on sorting lines using the 628 N push force at 0.5 MPa to push parcels reliably.
Replacing the Airtac SI40 Standard Cylinder SI40X1650S with the SAI40X1650S
To replace the SI40X1650S, order the SAI40X1650S to get the identical ISO 15552 mounting interface, 40 mm bore, 1650 mm stroke, G1/4 port and M12x1.25 rod thread. Retain your existing mounting accessory (LB, FA, TC, etc.) and confirm the magnet (-S) for position sensing. When sizing, consider neighbouring bores: a 32 mm bore gives 402 N push at 0.5 MPa, while a 50 mm bore yields 982 N. Note that 1650 mm is a non-standard made-to-order stroke exceeding the 1200 mm standard limit. At this extended length, prevent rod bending by using an external guide to absorb side loads. A plain cylinder does not hold load on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for held loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X1650S
- ✓ 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 SI40X1650S FAQ
Yes, the SI40X1650S is discontinued. The direct replacement is the SAI40X1650S. It is dimensionally interchangeable per ISO 15552, matching the 40 mm bore, 1650 mm stroke, G1/4 port, force and mounting fixtures.
This double-acting cylinder uses a G1/4 port and provides 628 N push and 528 N pull at 0.5 MPa. At 0.7 MPa it pushes 879 N, at 0.9 MPa 1130 N, with a theoretical max of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X1650S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X1650S replacement — usually within 7-8 hours.