This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X55, 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 SI50X55
The AirTAC Airtac SI50 Standard Cylinder SI50X55 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 SAI50X55, 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 → SAI50X55
- 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 SI50X55
The AirTAC SI50X55 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 55mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI50X55, matching the exact interface, force, and mounting.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. Note this non-S SKU lacks a magnet and cannot accept a CS1-B/DS1-B sensor.
Airtac SI50 Standard Cylinder SI50X55 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X55 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X55 |
| 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 SAI50X55 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 SAI50X55 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 SI50X55
| 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 SI50X55 Is Used
Short-Stroke Clamping
Ideal for holding workpieces in machining fixtures where a 55mm travel provides rapid actuation and 982N of force secures the part.
Package Diverting
Suitable for pushing light cartons off a belt line, using the 50mm bore to deliver swift lateral movement in tight spaces.
Gate Actuation
Operates small sorting gates or stops in material handling systems, offering reliable 50kg vertical lift capacity with a safety margin.
Replacing the Airtac SI50 Standard Cylinder SI50X55 with the SAI50X55
To replace the SI50X55, order the SAI50X55 ensuring the ISO 15552 mounting interface, 50mm bore, 55mm stroke, G1/4 port, and M16x1.5 rod thread match your fixture. If you need position sensing, you must select an SAI variant with the magnet option, as this plain SI unit cannot hold a switch. For sizing, a neighbouring 40mm bore yields 628N push at 0.5MPa, while a 63mm bore offers 1559N. The cushion only decelerates the load; it does not hold it. For load-holding on air loss, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X55
- ✓ 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 SI50X55 FAQ
Yes, the AirTAC SI50X55 is discontinued. The direct replacement is the SAI50X55. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 55mm stroke, output force, G1/4 port, and mounting accessories.
The G1/4 port feeds thrust figures of 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.
Request a Quote for the SAI50X55
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X55 replacement — usually within 7-8 hours.