This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X235, 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 SI50X235
The AirTAC Airtac SI50 Standard Cylinder SI50X235 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 235mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X235, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke235 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X235
- 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 SI50X235
The AirTAC SI50X235 is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 235 mm stroke, delivering 982 N push force at 0.5 MPa. AirTAC replaced this legacy unit with the SAI50X235, a direct upgrade retaining the exact G1/4 port, M16x1.5 rod thread, and 30 mm cushion. Because this specific SKU lacks the -S magnet suffix, it cannot accept a CS1-B or DS1-B sensor.
The SAI50X235 introduces an upgraded piston seal featuring two Y-shaped one-way elements for lower start-up pressure and longer life. Ratings and the ISO 15552 mounting interface remain unchanged. If high temperatures are involved, a Viton H seal option extends operation to 150 C.
Airtac SI50 Standard Cylinder SI50X235 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X235 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X235 |
| Bore size | Ø50 mm |
| Stroke | 235 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 SAI50X235 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 SAI50X235 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 SI50X235
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×235 | 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 SI50X235 Is Used
Package Diverting
Actuates routing gates on packaging lines where the 982 N push force easily overcomes friction on moderate carton weights.
Light Lift Stations
Raises lower platforms or tooling up to the 50 kg vertical limit, utilizing the 235 mm travel for brief elevation changes.
Pallet Stops
Deploys stopping fingers at roller conveyor ends, absorbing kinetic impact using the 30 mm adjustable air cushions.
Replacing the Airtac SI50 Standard Cylinder SI50X235 with the SAI50X235
To replace the discontinued SI50X235, order the SAI50X235. Confirm it matches your ISO 15552 mounting fixtures (LB, FA, TC, etc.), the 235 mm stroke, and the G1/4 port. Note that 235 mm is a nonstandard stroke length (standard increments skip from 200 to 250 mm), so verify your exact travel requirement. Because this SKU has no -S magnet, it cannot support position sensing; if you need switches, order the SAI50X235S instead and use current AirTAC sensors. For sizing both ways: this 50 mm bore yields 982 N push at 0.5 MPa; dropping to a 40 mm bore reduces push to 628 N, while stepping up to a 63 mm bore increases it to 1559 N. Since the stroke is 235 mm (over 200 mm), ensure adequate guide support to prevent rod bending and side-load wear. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external pilot check valve or the SAIL/BSAI lock variant for load holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X235
- ✓ 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 SI50X235 FAQ
Yes, the SI50X235 is discontinued. The direct replacement is the SAI50X235. It is dimensionally interchangeable per ISO 15552, matching the 50 mm bore, 235 mm stroke, G1/4 port, and mounting interface, but adds an upgraded two Y-shaped element piston seal.
The bore is 50 mm with a G1/4 air port. The output force is 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.
Request a Quote for the SAI50X235
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X235 replacement — usually within 7-8 hours.