This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX375S, 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 SI50AX375S
The AirTAC Airtac SI50 Standard Cylinder SI50AX375S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 375mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX375S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke375 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX375S
- 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 SI50AX375S
The AirTAC SI50AX375S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 375mm stroke, and a SUS420J2 stainless steel rod. Generating 982 N push force at 0.5 MPa, it is directly replaced by the SAI50AX375S direct equivalent. The SAI upgrade retains the exact G1/4 port, M16x1.5 thread, and 30mm cushions, but introduces an upgraded piston seal featuring two Y-shaped one-way elements for lower start-up pressure and longer life.
The built-in magnet supports legacy CS1-B/DS1-B sensors, while a Viton H seal option can elevate operating temperatures to 150 C. Note that the 375mm stroke requires external guides to prevent rod bending under side loads.
Airtac SI50 Standard Cylinder SI50AX375S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX375S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX375S |
| Bore size | Ø50 mm |
| Stroke | 375 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 SAI50AX375S 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 SAI50AX375S 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 SI50AX375S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×375 | 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 SI50AX375S Is Used
Diverting & Sorting
Drives diverter arms on packaging lines, using the 982 N push force at 0.5 MPa to shift products reliably across conveyor belts.
Stainless Rod Tooling
Actuates clamping or gating mechanisms in washdown areas, leveraging the SUS420J2 stainless steel rod for corrosion resistance.
Replacing the Airtac SI50 Standard Cylinder SI50AX375S with the SAI50AX375S
To replace the SI50AX375S, order the SAI50AX375S keeping the identical 50mm bore, 375mm stroke, G1/4 port, and ISO 15552 mounting interface. Verify your thread standard (PT, G, or NPT) and mounting accessory (LB, FA, TC, etc.) match. The -S magnet on this unit works with legacy CS1-B/DS1-B switches, though the SAI replacement family uses current AirTAC sensors. The -A suffix denotes the SUS420J2 stainless rod; confirm if you need this corrosion resistance or the standard carbon steel. For sizing, the neighboring 40mm bore yields 628 N push at 0.5 MPa, while the 63mm bore provides 1559 N. Because the 375mm stroke exceeds 300mm, use external guides to mitigate rod-bending and side-load risks. A plain cylinder drifts without live air; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX375S
- ✓ 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 SI50AX375S FAQ
Yes, the SI50AX375S is discontinued. The direct replacement is the AirTAC SAI50AX375S. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 375mm stroke, G1/4 port, and mounting interface, so it fits existing fixtures perfectly.
This double-acting cylinder features a G1/4 air port and M16x1.5 rod thread. It delivers 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and 1767 N push at 0.9 MPa. The theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX375S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX375S replacement — usually within 7-8 hours.