This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X655S, 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 SI50X655S
The AirTAC Airtac SI50 Standard Cylinder SI50X655S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 655mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X655S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke655 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X655S
- 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 SI50X655S
The AirTAC SI50X655S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 655mm stroke. It delivers 982 N push and 825 N pull at 0.5 MPa through a G1/4 port. The direct replacement is the SAI50X655S, matching the exact interface, force, and mounting.
Upgrading to the SAI brings an advanced two Y-shaped one-way piston seal for low start-up pressure. For sensing, this SI uses legacy CS1-B/DS1-B switches.
Airtac SI50 Standard Cylinder SI50X655S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X655S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X655S |
| Bore size | Ø50 mm |
| Stroke | 655 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 SAI50X655S 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 SAI50X655S 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 SI50X655S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×655 | 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 SI50X655S Is Used
Long-Stroke Diversion
Actuates routing gates on packaging lines, using the 655mm stroke to shift products between parallel conveyors.
Vertical Material Lift
Raises tote boxes up to 50 kg in pick modules, safely operating within the 982 N push force at 0.5 MPa.
Slide Table Indexing
Drives a heavy-duty linear slide through a 655mm cycle, relying on external guides to prevent rod side-loading.
Replacing the Airtac SI50 Standard Cylinder SI50X655S with the SAI50X655S
To replace the SI50X655S, order the SAI50X655S. Confirm the ISO 15552 mounting interface (LB, FA, TC, etc.), the G1/4 port, the M16x1.5 rod thread, and the -S magnet for CS1-B/DS1-B switches. The SAI family adds SAIL (air-released lock), SAIF (built-in 4M valve), and BSAI (clamp-lock) variants the SI lacked. A plain cylinder drifts on air loss; cushions only decelerate, so use an external rod lock or pilot check valve for load holding. At 655mm stroke, prevent rod bending by guiding the load externally. If downsizing, a 40mm bore gives 628 N push; if upsizing, a 63mm bore yields 1559 N.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X655S
- ✓ 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 SI50X655S FAQ
Yes, the SI50X655S is discontinued. The direct replacement is the SAI50X655S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 655mm stroke, G1/4 port, and mounting fixtures.
It features a G1/4 air port. 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 max of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X655S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X655S replacement — usually within 7-8 hours.