This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX50, 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 SI50AX50
The AirTAC SI50 Standard Cylinder SI50AX50 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 50mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX50, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke50 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX50
- 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 SI50AX50
The AirTAC SI50AX50 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 50mm stroke, delivering 982 N push force at 0.5 MPa. It features a Ø20mm rod, M16x1.5 thread, and G1/4 port. The direct replacement is the SAI50AX50, which retains the exact ISO 15552 mounting interface, bore, stroke, and output force for seamless fixture integration.
The SAI upgrade introduces an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Because this specific SKU lacks the -S magnet suffix, it cannot accept a position switch.
Airtac SI50 Standard Cylinder SI50AX50 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX50 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX50 |
| Bore size | Ø50 mm |
| Stroke | 50 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 SAI50AX50 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 SAI50AX50 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 SI50AX50
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×50 | 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 SI50AX50 Is Used
Short-Stroke Clamping
Ideal for holding workpieces in CNC machining fixtures, utilizing the 50mm stroke and 982 N push force to secure parts firmly during milling operations.
Package Diverting
Drives short-stroke diverters on packaging lines, providing the rapid 30-800 mm/s actuation needed to route boxes efficiently at transfer points.
Pallet Stop Gates
Acts as a pneumatic stop gate in conveyorized pallet handling systems, where the 50 kg vertical lift capacity and robust ISO 15552 profile withstand repeated impacts.
Replacing the Airtac SI50 Standard Cylinder SI50AX50 with the SAI50AX50
To replace the discontinued SI50AX50, order the SAI50AX50. Verify your ISO 15552 mounting interface (LB, FA, TC, etc.), the G1/4 port thread (PT/G/NPT), and the Ø20mm rod with M16x1.5 thread. Sizing checks: the 50mm bore yields 982 N push at 0.5 MPa; dropping to a 40mm bore gives 628 N, while a 63mm bore provides 1559 N. Note that a plain cylinder drifts on air loss—the cushion only decelerates—so add an external rod lock or pilot check valve for load holding. The SAI family also offers SAIL and BSAI lock variants if integrated holding is required.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX50
- ✓ 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 SI50AX50 FAQ
Yes, the SI50AX50 is discontinued. The direct replacement is the AirTAC SAI50AX50. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 50mm stroke, G1/4 port, and mounting interface, so it drops directly into existing fixtures.
The G1/4 port is fixed by the 50mm bore. At 0.5 MPa it provides 982 N push and 825 N pull force. At 0.7 MPa push is 1374 N, and at 0.9 MPa it is 1767 N. The theoretical maximum force is 200 kgf at 1.0 MPa.
Request a Quote for the SAI50AX50
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX50 replacement — usually within 7-8 hours.