This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX35S, 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 SI50AX35S
The AirTAC Airtac SI50 Standard Cylinder SI50AX35S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 35mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX35S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke35 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX35S
- 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 SI50AX35S
The AirTAC SI50AX35S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 35mm stroke, and a SUS420J2 stainless piston rod. Delivering 982 N push force at 0.5 MPa through a G1/4 port, its legacy search traffic now routes to the SAI50AX35S direct replacement.
The SAI50AX35S matches the exact ISO 15552 mounting interface, bore, stroke, and force while upgrading the piston seal to two Y-shaped one-way elements for lower start-up pressure. The built-in magnet supports CS1-B/DS1-B switches, and a Viton H seal option raises operating temps to 150 C.
Airtac SI50 Standard Cylinder SI50AX35S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX35S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX35S |
| Bore size | Ø50 mm |
| Stroke | 35 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 SAI50AX35S 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 SAI50AX35S 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 SI50AX35S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×35 | 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 SI50AX35S Is Used
Stainless Rod Clamping
Ideal for short-stroke clamping in packaging lines where the SUS420J2 rod resists moisture and the 982 N force secures parts firmly.
Compact Diverting
The 35mm stroke provides rapid actuation for diverting lightweight goods on conveyors, fitting tight ISO 15552 fixture spaces.
Replacing the Airtac SI50 Standard Cylinder SI50AX35S with the SAI50AX35S
To replace the discontinued SI50AX35S, order the SAI50AX35S, confirming the ISO 15552 interface, G1/4 port, M16x1.5 rod thread, and the -S magnet for legacy CS1-B/DS1-B sensors. The SUS420J2 stainless rod offers corrosion resistance over standard carbon steel. Sizing both ways: a 40mm bore yields 628 N at 0.5 MPa, while a 63mm bore provides 1559 N. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external pilot check valve or explore the SAIL or BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX35S
- ✓ 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 SI50AX35S FAQ
Yes, the SI50AX35S is discontinued. The direct replacement is the SAI50AX35S. It shares the identical ISO 15552 mounting interface, 50mm bore, 35mm stroke, force, and G1/4 port, fitting existing fixtures perfectly while upgrading the piston seal.
The bore is 50mm with a G1/4 air port. At 0.5 MPa it pushes 982 N and pulls 825 N. 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX35S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX35S replacement — usually within 7-8 hours.