This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X20TC, 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 SI50X20TC
The AirTAC Airtac SI50 Standard Cylinder SI50X20TC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 20mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X20TC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke20 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X20TC
- 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 SI50X20TC
The AirTAC SI50X20TC is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 20 mm stroke. It delivers 982 N push force at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI50X20TC, a direct upgrade sharing the exact TC trunnion mounting, stroke, output force and ISO 15552 interface dimensions.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. For sensing, note this specific SI SKU lacks a magnet and cannot accept a CS1-B/DS1-B switch.
Airtac SI50 Standard Cylinder SI50X20TC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X20TC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X20TC |
| Bore size | Ø50 mm |
| Stroke | 20 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 SAI50X20TC 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 SAI50X20TC 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 SI50X20TC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×20 | 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 SI50X20TC Is Used
Short-Stroke Clamping
Ideal for applying 982 N of clamping force in compact machining fixtures where only a 20 mm travel is required.
Part Ejection
Provides a fast 30-800 mm/s ejection thrust for small stamped or molded components exiting a press die.
Stopper Gate
Functions as a pneumatic stopper in conveyor lines, lowering to halt 50 kg workpiece carriers on demand.
Replacing the Airtac SI50 Standard Cylinder SI50X20TC with the SAI50X20TC
To replace the SI50X20TC, order the SAI50X20TC and confirm the ISO 15552 TC trunnion interface, 50 mm bore, 20 mm stroke and G1/4 port. Because this SKU lacks a magnet (-S), it cannot support legacy CS1-B/DS1-B sensors; order a magnet-equipped SAI if position detection is needed. Sizing both ways: a 40 mm bore yields 628 N push at 0.5 MPa, while a 63 mm bore yields 1559 N. The standard cylinder does not hold load without live air; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variants. The 20 mm stroke is very short, so side-load risks are minimal, but ensure rigid TC mounting to prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X20TC
- ✓ 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 SI50X20TC FAQ
Yes, the SI50X20TC is discontinued. The direct replacement is the SAI50X20TC. It shares the same ISO 15552 mounting interface, 50 mm bore, 20 mm stroke, force and G1/4 port, fitting existing TC trunnion fixtures perfectly.
This double-acting cylinder uses a G1/4 air port. At 0.5 MPa it provides 982 N push and 825 N pull force. 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 SAI50X20TC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X20TC replacement — usually within 7-8 hours.