This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X650S, 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 SI50X650S
The AirTAC Airtac SI50 Standard Cylinder SI50X650S 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 SAI50X650S, 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 → SAI50X650S
- 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 SI50X650S
The AirTAC SI50X650S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 650mm stroke. It delivers 982N push and 825N pull at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X650S, a direct sharing the exact ISO 15552 mounting interface, bore, stroke, force and port.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The -S magnet works with CS1-B/DS1-B switches, while SAIL lock and SAIF valve variants expand options.
Airtac SI50 Standard Cylinder SI50X650S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X650S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X650S |
| 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 SAI50X650S 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 SAI50X650S 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 SI50X650S
| 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 SI50X650S Is Used
Long-Stroke Diversion
Pushes packages across transfer lines with 982N push @0.5MPa, using the 650mm travel to clear adjacent lanes.
Press Ejection
Cycles formed parts out of machinery beds, utilizing the 30mm adjustable air cushions to decelerate at stroke end.
Replacing the Airtac SI50 Standard Cylinder SI50X650S with the SAI50X650S
To replace the SI50X650S, order the SAI50X650S. Confirm the ISO 15552 interface, 50mm bore, 650mm stroke, G1/4 port (PT/G/NPT thread), M16x1.5 rod thread and mounting accessory. The -S magnet enables CS1-B/DS1-B sensors. For sizing, the 40mm bore yields 628N push @0.5MPa, while the 63mm bore yields 1559N. Note: a plain cylinder drifts on air loss; the 30mm cushions only decelerate. For load holding, use an external rod lock, pilot check valve, or SAIL/BSAI variant. At 650mm, prevent rod bending by using external guides to manage side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X650S
- ✓ 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 SI50X650S FAQ
Yes, the SI50X650S is discontinued. The direct replacement is the SAI50X650S. It shares the identical ISO 15552 mounting interface, 50mm bore, 650mm stroke, output force, G1/4 port and mounting accessories, fitting directly into existing fixtures.
This double-acting cylinder has a G1/4 port and M16x1.5 rod thread. It delivers 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical max of 200kgf at 1.0MPa. Operating speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X650S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X650S replacement — usually within 7-8 hours.