This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X140S, 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 SI50X140S
The AirTAC Airtac SI50 Standard Cylinder SI50X140S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 140mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X140S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke140 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X140S
- 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 SI50X140S
The AirTAC SI50X140S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 140mm stroke. Delivering 982N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI50X140S. This direct upgrade shares the exact ISO 15552 mounting interface, bore, stroke, output force, port size and accessories.
The SAI successor features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. It also adds SAIL, SAIF and BSAI variants the SI lacked. This -S model has a piston magnet for CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X140S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X140S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X140S |
| Bore size | Ø50 mm |
| Stroke | 140 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 SAI50X140S 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 SAI50X140S 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 SI50X140S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×140 | 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 SI50X140S Is Used
Package Diverting
Actuates diverter arms on packaging lines using the 982N push force to reliably shift cartons at speeds up to 800 mm/s.
Clamp Actuation
Drives mid-force clamping fixtures for CNC machining, utilizing the 140mm stroke to accommodate varying part widths.
Replacing the Airtac SI50 Standard Cylinder SI50X140S with the SAI50X140S
To replace the SI50X140S, order the SAI50X140S. Verify the ISO 15552 mounting interface, 50mm bore, 140mm stroke, G1/4 port (PT/G/NPT) and your mounting accessory. The -S suffix means a magnet is present for CS1-B/DS1-B switches; the SAI uses current AirTAC switches. Sizing both ways: a 40mm bore yields 628N push @0.5MPa, while a 63mm bore yields 1559N. A plain cylinder drifts on air loss as the cushion only decelerates; for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. For 140mm stroke, side-load risk is low, but ensure guide alignment to prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X140S
- ✓ 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 SI50X140S FAQ
Yes, the SI50X140S is discontinued. The direct replacement is the SAI50X140S. It shares the same ISO 15552 mounting interface, 50mm bore, 140mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly while upgrading the piston seal.
The G1/4 port bore delivers 982N push and 825N pull at 0.5 MPa, 1374N push at 0.7 MPa, 1767N at 0.9 MPa, and a theoretical max of 200 kgf at 1.0 MPa. Operating pressure is 0.15-1.0 MPa with a 30mm adjustable air cushion at each end.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X140S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X140S replacement — usually within 7-8 hours.