This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X75STC, 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 SI50X75STC
The AirTAC Airtac SI50 Standard Cylinder SI50X75STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 75mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X75STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke75 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X75STC
- 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 SI50X75STC
The AirTAC SI50X75STC is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 75mm stroke. It delivers a push force of 982 N at 0.5 MPa via a G1/4 port. The direct replacement is the SAI50X75STC, which retains the same interface, TC trunnion mount, and output force.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This -S model includes a magnet for legacy CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches.
Airtac SI50 Standard Cylinder SI50X75STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X75STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X75STC |
| Bore size | Ø50 mm |
| Stroke | 75 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 SAI50X75STC 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 SAI50X75STC 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 SI50X75STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×75 | 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 SI50X75STC Is Used
Material Diversion
Drives 75mm stroke sorter flaps on packaging lines, providing 982 N of push force to redirect cartons reliably at line speeds.
Clamp Actuation
Secures medium workpieces in machining fixtures using the TC trunnion mount, handling a safe 589 N working load during milling.
Replacing the Airtac SI50 Standard Cylinder SI50X75STC with the SAI50X75STC
To replace the SI50X75STC, order the SAI50X75STC. Confirm the ISO 15552 TC trunnion mounting interface, 50mm bore, 75mm stroke, G1/4 port, and the -S magnet. Sizing context: a 40mm bore yields 628 N push at 0.5 MPa, while a 63mm bore yields 1559 N. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variants. The SAI family also adds the SAIF self-valve option.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X75STC
- ✓ 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 SI50X75STC FAQ
Yes, the SI50X75STC is discontinued. The direct replacement is the SAI50X75STC. It is dimensionally interchangeable per ISO 15552, keeping the same 50mm bore, 75mm stroke, G1/4 port, TC mount, and force ratings.
The 50mm bore uses a G1/4 air port. At 0.5 MPa it pushes 982 N and pulls 825 N. At 0.7 MPa it pushes 1374 N, and 1767 N at 0.9 MPa. The theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X75STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X75STC replacement — usually within 7-8 hours.