This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X650STC, 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 SI50X650STC
The AirTAC Airtac SI50 Standard Cylinder SI50X650STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 650mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X650STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke650 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X650STC
- 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 SI50X650STC
The AirTAC SI50X650STC is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 650mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI50X650STC, matching the exact bore, stroke, force, and TC mounting interface.
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. Your -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X650STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X650STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X650STC |
| Bore size | Ø50 mm |
| Stroke | 650 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 SAI50X650STC 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 SAI50X650STC 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 SI50X650STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×650 | 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 SI50X650STC Is Used
Long-Stroke Diversion
Pushes packages across transfer lines with 982N force, using the 650mm travel to bridge conveyor lanes.
Automated Forming Press
Actuates tooling over 650mm to clear workpieces, utilizing the adjustable 30mm air cushions to decelerate at ends.
Replacing the Airtac SI50 Standard Cylinder SI50X650STC with the SAI50X650STC
To replace the SI50X650STC, order the SAI50X650STC. Confirm the ISO 15552 TC trunnion mount, 650mm stroke, G1/4 port, and -S magnet. Sizing up or down: a 40mm bore gives 628N push, while a 63mm bore yields 1559N at 0.5MPa. Note that a plain cylinder drifts on air loss; for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. At 650mm stroke, use an external guide to prevent rod bending and side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X650STC
- ✓ 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 SI50X650STC FAQ
Yes, the SI50X650STC is discontinued. The direct replacement is the SAI50X650STC, which is dimensionally interchangeable per ISO 15552 with the same bore, stroke, force, G1/4 port, and TC mounting.
It uses a G1/4 port. Force ratings are 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical max of 200 kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X650STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X650STC replacement — usually within 7-8 hours.