This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X640S, 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 SI50 Standard Cylinder SI50X640S
The AirTAC Airtac SI50 Standard Cylinder SI50X640S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 640mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X640S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke640 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X640S
- 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 SI50 Standard Cylinder SI50X640S
The AirTAC SI50X640S is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 640 mm stroke. It delivers 982 N push force at 0.5 MPa via a G1/4 port. The direct replacement is the SAI50X640S, matching the exact bore, stroke, force, and ISO 15552 mounting interface for existing fixtures.
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 lock variants the SI lacked. This -S SKU includes a piston magnet for legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X640S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X640S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X640S |
| Bore size | Ø50 mm |
| Stroke | 640 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M16×1.5 |
| 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, 30 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI50X640S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø50mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 kgf | |
The SAI50X640S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI50 Standard Cylinder SI50X640S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×640 | 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 SI50 Standard Cylinder SI50X640S Is Used
Long-Stroke Diversion
Pushes packages across transfer lines with a 640 mm reach, utilizing the 982 N push force at 0.5 MPa to overcome guide friction.
Multi-Station Indexing
Shifts machining pallets between stations, relying on the 30 mm adjustable air cushions to decelerate the payload smoothly.
Replacing the Airtac SI50 Standard Cylinder SI50X640S with the SAI50X640S
To replace the SI50X640S, order the SAI50X640S. Confirm the ISO 15552 mounting interface, 50 mm bore, 640 mm stroke, G1/4 port (PT/G/NPT), and mounting accessory. The -S magnet supports CS1-B/DS1-B switches, while the SAI uses current AirTAC sensors. Sizing both ways: a 40 mm bore yields 628 N [email protected], and a 63 mm bore yields 1559 N. For this 640 mm stroke, use external guides to prevent rod bending and side-load wear. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X640S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI50 Standard Cylinder SI50X640S FAQ
Yes, the SI50X640S is discontinued. The direct replacement is the SAI50X640S. It is dimensionally interchangeable per ISO 15552, retaining the same 50 mm bore, 640 mm stroke, G1/4 port, and mounting interface.
It features a G1/4 air port. The force ratings are: 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X640S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X640S replacement — usually within 7-8 hours.