This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X210STC, 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 SI50X210STC
The AirTAC Airtac SI50 Standard Cylinder SI50X210STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 210mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X210STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke210 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X210STC
- 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 SI50X210STC
The AirTAC SI50X210STC is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 210mm stroke, and TC trunnion mounting. Delivering 982N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI50X210STC. This direct upgrade matches the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. It also adds SAIL, SAIF, and BSAI lock variants the SI lacked. For sensing, the -S magnet works with legacy CS1-B/DS1-B switches.
Airtac SI50 Standard Cylinder SI50X210STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X210STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X210STC |
| Bore size | Ø50 mm |
| Stroke | 210 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 SAI50X210STC 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 SAI50X210STC 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 SI50X210STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×210 | 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 SI50X210STC Is Used
Mid-Range Conveyor Diverter
Uses the 982N push force at 0.5MPa and TC trunnion mount to push medium-weight packages onto parallel conveyor lines.
Component Clamping Station
Secures aluminium housings during machining, using the adjustable 30mm air cushion to decelerate the 20mm rod smoothly.
Replacing the Airtac SI50 Standard Cylinder SI50X210STC with the SAI50X210STC
To replace the SI50X210STC, order the SAI50X210STC. It is a direct per the ISO 15552 mounting interface, keeping the 50mm bore, 210mm stroke, G1/4 port, M16x1.5 rod thread, and TC trunnion mount. Note that 210mm is a nonstandard stroke (max standard is 1200mm), so confirm lead times. Because 210mm exceeds 300mm, ensure adequate guidance to prevent rod bending under side loads. For sizing, neighbouring bores are 40mm (628N push @0.5MPa) and 63mm (1559N push). A plain cylinder drifts on air loss; the 30mm cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variant. The -S magnet supports CS1-B/DS1-B sensors.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X210STC
- ✓ 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 SI50X210STC FAQ
Yes, the SI50X210STC is discontinued. The direct replacement is the SAI50X210STC. It shares the identical ISO 15552 mounting interface, 50mm bore, 210mm stroke, G1/4 port, and TC trunnion mount, fitting existing fixtures perfectly.
This double-acting cylinder uses a G1/4 port. It delivers 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical max of 200kgf at 1.0MPa. The rod is 20mm with an M16x1.5 thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X210STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X210STC replacement — usually within 7-8 hours.