This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX275S, 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 SI50AX275S
The AirTAC SI50 Standard Cylinder SI50AX275S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 275mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX275S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke275 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX275S
- 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 SI50AX275S
The AirTAC SI50AX275S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore, 275mm stroke, and a SUS420J2 stainless steel rod. Delivering 982 N push at 0.5 MPa, it is replaced by the SAI50AX275S. This direct upgrade shares the exact ISO 15552 mounting interface, G1/4 port, and force, fitting existing fixtures seamlessly.
The SAI replacement upgrades the piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. The original -S magnet supports legacy CS1-B/DS1-B sensors, while the SAI family also adds SAIL, SAIF, and BSAI variants.
Airtac SI50 Standard Cylinder SI50AX275S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX275S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX275S |
| Bore size | Ø50 mm |
| Stroke | 275 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 SAI50AX275S 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 SAI50AX275S 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 SI50AX275S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×275 | 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 SI50AX275S Is Used
Stainless Rod Clamping
Ideal for packaging lines where the SUS420J2 stainless rod resists washdown moisture while providing 982 N of clamping force.
Mid-Stroke Diverting
The 275mm stroke offers extended reach for pushing products between parallel conveyor lanes without requiring external guides.
Replacing the Airtac SI50 Standard Cylinder SI50AX275S with the SAI50AX275S
To replace the SI50AX275S, order the SAI50AX275S. Verify the ISO 15552 mounting interface, 275mm stroke, G1/4 port, and the -S magnet. The -A rod material denotes a SUS420J2 stainless piston rod for corrosion resistance. For sizing, neighbouring bores are 40mm (628 N push @0.5) and 63mm (1559 N push @0.5). Since the 275mm stroke exceeds 300mm, ensure adequate guide support to prevent rod bending and side-load wear. A plain cylinder does not hold load without live air; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX275S
- ✓ 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 SI50AX275S FAQ
Yes, the SI50AX275S is discontinued. The direct replacement is the SAI50AX275S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 275mm stroke, G1/4 port, and mounting interface.
This double-acting cylinder has a G1/4 air port. The force output is 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX275S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX275S replacement — usually within 7-8 hours.