This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X25TC, 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 SI50X25TC
The AirTAC Airtac SI50 Standard Cylinder SI50X25TC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 25mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X25TC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke25 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X25TC
- 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 SI50X25TC
The AirTAC SI50X25TC is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 25mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X25TC, a direct sharing the exact TC trunnion mount, M16x1.5 rod thread, and dimensions. The SAI features an upgraded piston seal with two Y-shaped elements for low start-up pressure.
This non-magnet SKU cannot accept position sensors, unlike legacy CS1-B/DS1-B switches. The SAI family also adds SAIL, SAIF, and BSAI lock variants absent in the SI line.
Airtac SI50 Standard Cylinder SI50X25TC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X25TC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X25TC |
| Bore size | Ø50 mm |
| Stroke | 25 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 SAI50X25TC 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 SAI50X25TC 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 SI50X25TC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×25 | 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 SI50X25TC Is Used
Short-Stroke Clamping
Ideal for applying 982N of clamping force in tight machining fixtures where only a 25mm travel is required.
Package Diverting
Provides rapid 30-800mm/s actuation for diverting lightweight packages on a TC trunnion-mounted assembly.
Pallet Stops
Functions as a reliable pneumatic stop gate for pallets, utilizing its 825N pull force to retract out of the path.
Replacing the Airtac SI50 Standard Cylinder SI50X25TC with the SAI50X25TC
To replace the SI50X25TC, order the SAI50X25TC ensuring the TC trunnion mounting interface and G1/4 port match your fixture. This non-magnet version cannot support sensors; order an SAI with the S suffix if you need CS1-B/DS1-B equivalent switches. The 50mm bore yields 982N push at 0.5MPa; step down to a 40mm bore (628N) or up to a 63mm bore (1559N) to tune force. A plain cylinder drifts on air loss—the cushion only decelerates—so use a pilot check valve or SAIL lock for held loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X25TC
- ✓ 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 SI50X25TC FAQ
Yes, the SI50X25TC is discontinued. The direct replacement is the SAI50X25TC. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 25mm stroke, G1/4 port, and TC mounting interface.
The 50mm bore uses a G1/4 air port. It generates 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical maximum of 200kgf at 1.0MPa. It features a 20mm rod and 30mm adjustable cushions.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X25TC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X25TC replacement — usually within 7-8 hours.