This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X325STC, 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 SI50X325STC
The AirTAC Airtac SI50 Standard Cylinder SI50X325STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 325mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X325STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke325 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X325STC
- 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 SI50X325STC
The AirTAC SI50X325STC is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 325mm stroke, delivering 982N push force at 0.5MPa via a G1/4 port. It is replaced by the direct replacement SAI50X325STC.
The SAI upgrade retains the exact ISO 15552 mounting interface and adds a two Y-shaped one-way piston seal for low start-up pressure. The family adds SAIL lock and BSAI clamp variants.
Airtac SI50 Standard Cylinder SI50X325STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X325STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X325STC |
| Bore size | Ø50 mm |
| Stroke | 325 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 SAI50X325STC 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 SAI50X325STC 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 SI50X325STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×325 | 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 SI50X325STC Is Used
Package Diversion
Actuates routing gates on packaging lines where the 982N push force at 0.5MPa easily deflects standard totes.
End-of-Arm Tooling
Drives simple gripper assemblies on stationary automation, utilizing the TC trunnion mount for pivoting articulation.
Replacing the Airtac SI50 Standard Cylinder SI50X325STC with the SAI50X325STC
To replace the SI50X325STC, order the SAI50X325STC keeping the TC trunnion mount, 325mm stroke, and S magnet for CS1-B/DS1-B switches. If sizing up or down, neighboring bores are 40mm (628N push) and 63mm (1559N push) at 0.5MPa. A plain cylinder drifts without air; for load holding use an external pilot check valve or the SAIL/BSAI lock variants. At 325mm, use external guides to prevent rod bending from side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X325STC
- ✓ 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 SI50X325STC FAQ
Yes, the SI50X325STC is discontinued. The direct replacement is the SAI50X325STC, which matches the ISO 15552 mounting interface, 50mm bore, 325mm stroke, force, G1/4 port, and TC mounting.
The G1/4 port bore delivers 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N at 0.9MPa, and a maximum theoretical force of 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X325STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X325STC replacement — usually within 7-8 hours.