This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X70S, 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 SI50X70S
The AirTAC Airtac SI50 Standard Cylinder SI50X70S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 70mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X70S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke70 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X70S
- 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 SI50X70S
The AirTAC SI50X70S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 70mm stroke, delivering 982N push force at 0.5MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI50X70S, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke, output force, port size and accessories. The SAI features an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. For position sensing, this -S SKU has a built-in piston magnet for legacy CS1-B/DS1-B switches, while the SAI replacement family uses current AirTAC switches. The SAI family also adds variants the SI lacked: SAIL (air-released lock), SAIF (built-in 4M valve) and BSAI (clamp-lock). Seal options include standard NBR and Viton H for high-temperature environments up to 150C.
Airtac SI50 Standard Cylinder SI50X70S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X70S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X70S |
| Bore size | Ø50 mm |
| Stroke | 70 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 SAI50X70S 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 SAI50X70S 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 SI50X70S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×70 | 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 SI50X70S Is Used
Package Diversion
Ideal for pushing 50kg cartons onto adjacent conveyor lanes using the 70mm stroke and 982N force at 0.5MPa.
Stopper Gate
Functions as a pneumatic stopper for material handling lines, with the magnet enabling precise end-position confirmation.
Replacing the Airtac SI50 Standard Cylinder SI50X70S with the SAI50X70S
To replace the SI50X70S, order the SAI50X70S and confirm the ISO 15552 mounting interface, 50mm bore, 70mm stroke, G1/4 port (PT/G/NPT thread options), and your mounting accessory (LB, FA, CA, TC, etc.). The -S suffix means a magnet is present for position sensing; if your fixture used CS1-B/DS1-B switches, upgrade to current AirTAC sensors for the SAI. If you need to size up or down, neighbouring bores are 40mm and 63mm; at 0.5MPa, the 40mm yields 628N push while the 63mm yields 1559N. Note that a plain SI or SAI cylinder does not hold load on air loss or when the valve is centered—the cushion only decelerates near stroke end. For load-holding, consider an external rod lock, a pilot-operated check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X70S
- ✓ 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 SI50X70S FAQ
Yes, the SI50X70S is discontinued. The direct replacement is the SAI50X70S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 70mm stroke, G1/4 port, and mounting interface, so it drops directly into existing fixtures.
The 50mm bore uses a G1/4 air port. Force ratings are: 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical maximum of 200kgf at 1.0MPa. Operating speed is 30-800mm/s.
Request a Quote for the SAI50X70S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X70S replacement — usually within 7-8 hours.