This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX20, 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 SI50AX20
The AirTAC Airtac SI50 Standard Cylinder SI50AX20 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 20mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX20, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke20 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX20
- 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 SI50AX20
The AirTAC SI50AX20 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 20mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI50AX20, matching the exact bore, stroke, force, port and ISO 15552 mounting interface.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This non-magnet SKU cannot take a sensor, unlike the CS1-B/DS1-B compatible -S versions. The -A rod is SUS420J2 stainless.
Airtac SI50 Standard Cylinder SI50AX20 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX20 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX20 |
| Bore size | Ø50 mm |
| Stroke | 20 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 SAI50AX20 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 SAI50AX20 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 SI50AX20
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×20 | 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 SI50AX20 Is Used
Short-Stroke Clamping
Ideal for holding parts during machining with 982N push force at 0.5 MPa in compact fixtures.
Package Diverting
Provides rapid 20mm actuation for routing lightweight cartons on automated packaging lines.
Ejector Mechanisms
Delivers fast ejection of small parts using the 30-800 mm/s speed range and 825N pull force.
Replacing the Airtac SI50 Standard Cylinder SI50AX20 with the SAI50AX20
To replace the SI50AX20, order the SAI50AX20. Confirm the ISO 15552 mounting interface, 50mm bore, 20mm stroke, G1/4 port (PT/G/NPT thread) and -A SUS420J2 stainless rod. This SKU lacks a magnet (-S) so it cannot accept a CS1-B/DS1-B sensor. For sizing, a 40mm bore yields 628N [email protected], while a 63mm bore yields 1559N. The air cushion only decelerates; it does not hold load on air loss. For held loads use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX20
- ✓ 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 SI50AX20 FAQ
Yes, the SI50AX20 is discontinued. The direct replacement is the SAI50AX20. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 20mm stroke, 982N force, G1/4 port and mounting interface.
The G1/4 port feeds a 50mm bore yielding 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical max of 200kgf at 1.0MPa. The rod is 20mm with an M16x1.5 thread.
Request a Quote for the SAI50AX20
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX20 replacement — usually within 7-8 hours.