This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X250SFA, 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 SI50X250SFA
The AirTAC Airtac SI50 Standard Cylinder SI50X250SFA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 250mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X250SFA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke250 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X250SFA
- 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 SI50X250SFA
The AirTAC SI50X250SFA is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 250mm stroke. Delivering 982N push force at 0.5MPa via a G1/4 port, its legacy production has ended. The direct is the SAI50X250SFA, matching the exact FA flange mounting, M16x1.5 rod thread, and output force.
The SAI replacement upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life. The SAI family also introduces lock and valve variants (SAIL, BSAI, SAIF) absent in the SI line, and the built-in magnet here supports legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X250SFA Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X250SFA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X250SFA |
| Bore size | Ø50 mm |
| Stroke | 250 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 SAI50X250SFA 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 SAI50X250SFA 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 SI50X250SFA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×250 | 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 SI50X250SFA Is Used
Package Diverting
Drives diverting arms on packaging lines where the 982N push force easily redirects standard totes.
Clamp Actuation
Secures medium workpieces in machining fixtures, relying on the FA flange for rigid mounting.
Replacing the Airtac SI50 Standard Cylinder SI50X250SFA with the SAI50X250SFA
To replace the SI50X250SFA, order the SAI50X250SFA. It drops directly into existing fixtures via the ISO 15552 mounting interface, preserving the 50mm bore, 250mm stroke, G1/4 port, FA flange, and magnet. If you need more force, the neighbouring 63mm bore yields 1559N at 0.5MPa; if less is required, the 40mm bore provides 628N. Because this is a 250mm stroke, ensure your mechanical guide handles side loads to prevent rod bending. A standard cylinder drifts on air loss, so for load holding use an external pilot check valve or explore the SAIL/BSAI lock variants. The -S magnet enables CS1-B/DS1-B switches.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X250SFA
- ✓ 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 SI50X250SFA FAQ
Yes, the SI50X250SFA is discontinued. The direct replacement is the SAI50X250SFA. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 250mm stroke, G1/4 port, FA flange mount, and 982N force.
This double-acting cylinder features a G1/4 air port. It delivers 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and 1767N push at 0.9MPa. The theoretical maximum force is 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X250SFA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X250SFA replacement — usually within 7-8 hours.