This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX140S, 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 SI50AX140S
The AirTAC Airtac SI50 Standard Cylinder SI50AX140S 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 SAI50AX140S, 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 → SAI50AX140S
- 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 SI50AX140S
The AirTAC SI50AX140S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore, 140mm stroke, and a SUS420J2 stainless steel rod. It delivers 982 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50AX140S, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke, and output force.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The -S suffix denotes a piston magnet for legacy CS1-B/DS1-B sensors, while the -A rod provides corrosion resistance over standard carbon steel.
Airtac SI50 Standard Cylinder SI50AX140S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX140S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX140S |
| 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 SAI50AX140S 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 SAI50AX140S 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 SI50AX140S
| 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 SI50AX140S Is Used
Diverting Gate Actuation
Drives routing flaps on packaging lines where the 982 N push force at 0.5 MPa easily overcomes flap inertia and product friction.
Vertical Lift Stops
Raises 50 kg pallet stops in low-rise logistics hubs, utilizing the SUS420J2 stainless rod to resist humidity-induced corrosion.
Clamp Positioning
Moves lightweight machining clamps through a 140mm travel, relying on the 30mm adjustable air cushions to prevent end-of-stroke impact.
Replacing the Airtac SI50 Standard Cylinder SI50AX140S with the SAI50AX140S
To replace the SI50AX140S, order the SAI50AX140S. Verify your ISO 15552 mounting accessories (LB, FA, TC, etc.), the G1/4 air port, and the M16x1.5 rod thread. The 140mm stroke is standard and under the 1200mm maximum, so no side-load guide is strictly required, but always minimize rod bending. If you need to upsize, a 63mm bore offers 1559 N push at 0.5 MPa; downsizing to a 40mm bore drops force to 628 N. Note that a plain SAI does not hold load without live air—the cushions only decelerate. For fail-safe holding, specify the SAIL or BSAI lock variant, or use an external pilot check valve. The SAI family also adds the SAIF self-valve option (bores 32-100) absent in the SI line.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX140S
- ✓ 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 SI50AX140S FAQ
Yes, the SI50AX140S is discontinued. The direct replacement is the AirTAC SAI50AX140S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 140mm stroke, G1/4 port, and mounting interface, so it fits existing fixtures directly.
This double-acting cylinder uses a G1/4 air port and delivers a push force of 982 N and a pull force of 825 N at 0.5 MPa. At 0.7 MPa the push force is 1374 N, and at 0.9 MPa it is 1767 N. The theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX140S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX140S replacement — usually within 7-8 hours.