This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X140STC, 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 SI50X140STC
The AirTAC Airtac SI50 Standard Cylinder SI50X140STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 140mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X140STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke140 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X140STC
- 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 SI50X140STC
The AirTAC SI50X140STC is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 140mm stroke. It delivers a push force of 982 N and pull of 825 N at 0.5 MPa. The direct replacement is the SAI50X140STC, matching the G1/4 port, M16x1.5 rod thread and TC trunnion mount.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. The SAI family adds SAIL, SAIF and BSAI lock variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X140STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X140STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X140STC |
| Bore size | Ø50 mm |
| Stroke | 140 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 SAI50X140STC 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 SAI50X140STC 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 SI50X140STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×140 | 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 SI50X140STC Is Used
Package Diversion
Actuates routing gates on packaging lines, using the 140mm stroke to shift boxes cleanly between conveyors.
Clamp Actuation
Provides reliable clamping force for mid-weight machining fixtures, pushing with 982 N at 0.5 MPa.
Replacing the Airtac SI50 Standard Cylinder SI50X140STC with the SAI50X140STC
To replace the SI50X140STC, order the SAI50X140STC. Verify the ISO 15552 TC trunnion interface, 50mm bore, 140mm stroke, G1/4 port and -S magnet. Sizing both ways: a 40mm bore yields 628 N push at 0.5 MPa, while a 63mm bore yields 1559 N. The standard 50mm bore gives 982 N (1374 N at 0.7 MPa). For load holding, note a plain cylinder drifts on air loss as cushions only decelerate; use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. At 140mm stroke, rod bending is low, but ensure guide alignment to prevent side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X140STC
- ✓ 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 SI50X140STC FAQ
Yes, the SI50X140STC is discontinued. The direct replacement is the SAI50X140STC. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 140mm stroke, G1/4 port, TC mounting and output force.
The 50mm bore features a G1/4 air port. Force output is 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X140STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X140STC replacement — usually within 7-8 hours.