This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X125FA, 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 SI50X125FA
The AirTAC Airtac SI50 Standard Cylinder SI50X125FA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 125mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X125FA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke125 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X125FA
- 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 SI50X125FA
The AirTAC SI50X125FA is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 125mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X125FA, a direct sharing the exact FA flange mounting, M16x1.5 rod thread, and output force.
The SAI upgrade features a revised piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. Note this SKU lacks a magnet (-S) and cannot accept a CS1-B/DS1-B sensor. The SAI family also adds SAIL lock, SAIF valve, and BSAI clamp variants.
Airtac SI50 Standard Cylinder SI50X125FA Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X125FA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X125FA |
| Bore size | Ø50 mm |
| Stroke | 125 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 SAI50X125FA 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 SAI50X125FA 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 SI50X125FA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×125 | 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 SI50X125FA Is Used
Clamp Actuation
Provides 982N of clamping thrust at 0.5MPa for securing mid-weight workpieces during machining operations.
Package Diverting
Drives a 125mm stroke diverting arm to redirect goods on packaging lines without requiring complex linkages.
Replacing the Airtac SI50 Standard Cylinder SI50X125FA with the SAI50X125FA
To replace the SI50X125FA, order the SAI50X125FA. It drops into existing fixtures using the same ISO 15552 FA flange interface, 50mm bore, 125mm stroke, and G1/4 port. Because this specific SKU has no magnet, it cannot support position sensing; if detection is needed, specify an SAI50X125FA-S and use current AirTAC switches. When sizing, the 50mm bore yields 982N push at 0.5MPa; dropping to a 40mm bore reduces push to 628N, while a 63mm bore increases it to 1559N. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X125FA
- ✓ 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 SI50X125FA FAQ
Yes, the SI50X125FA is discontinued. The direct replacement is the SAI50X125FA. It shares the identical ISO 15552 FA flange mounting interface, 50mm bore, 125mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
The bore uses a G1/4 air port. At 0.5MPa it provides 982N push and 825N pull force. At 0.7MPa push is 1374N, and at 0.9MPa it is 1767N. The theoretical maximum force is 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X125FA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X125FA replacement — usually within 7-8 hours.