This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX55, 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 SI50AX55
The AirTAC Airtac SI50 Standard Cylinder SI50AX55 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 55mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX55, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke55 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX55
- 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 SI50AX55
The AirTAC SI50AX55 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 55mm stroke, delivering 982N push force at 0.5MPa. The direct replacement is the SAI50AX55, which matches the exact interface, port (G1/4), and output. This SKU features a SUS420J2 stainless piston rod for corrosion resistance. Lacking the -S suffix, it cannot accept a magnetic sensor. The SAI upgrade introduces a two-piece Y-shaped piston seal for lower start-up pressure, and adds SAIL, SAIF, and BSAI variants absent from the SI line.
Note that a standard cylinder drifts on air loss; the cushion only decelerates near stroke end. For load holding, use an external pilot check valve or the SAIL lock variant.
Airtac SI50 Standard Cylinder SI50AX55 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX55 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX55 |
| Bore size | Ø50 mm |
| Stroke | 55 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 SAI50AX55 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 SAI50AX55 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 SI50AX55
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×55 | 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 SI50AX55 Is Used
Stainless Rod Clamping
Ideal for moderate-force clamping tasks where the SUS420J2 rod resists moisture and environmental corrosion better than standard carbon steel.
Short-Stroke Diversion
The 55mm stroke provides precise actuation for package routing gates or pusher arms on 50mm bore ISO 15552 conveyor assemblies.
Replacing the Airtac SI50 Standard Cylinder SI50AX55 with the SAI50AX55
To replace the SI50AX55, order the SAI50AX55. Verify your ISO 15552 mounting fixtures, the G1/4 air port, and the M16x1.5 rod thread. Because this specific SKU lacks the -S magnet, it cannot support legacy CS1-B/DS1-B switches; order a magnet-equipped SAI if sensing is required. If sizing up, the 63mm bore yields 1559N at 0.5MPa; if sizing down, the 40mm bore yields 628N. For load holding on air loss, remember the cushion only decelerates and cannot lock the piston—specify an external rod lock or the SAIL/BSAI variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX55
- ✓ 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 SI50AX55 FAQ
Yes, the SI50AX55 is discontinued. The direct replacement is the SAI50AX55. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 55mm stroke, 982N force, G1/4 port, and mounting interface.
It features a G1/4 air port. Force output is 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical maximum of 200kgf at 1.0MPa. Operating speed is 30-800mm/s.
Request a Quote for the SAI50AX55
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX55 replacement — usually within 7-8 hours.