This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X70STC, 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 SI50X70STC
The AirTAC SI50 Standard Cylinder SI50X70STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 70mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X70STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke70 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X70STC
- 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 SI50X70STC
The AirTAC SI50X70STC is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 70 mm stroke. It delivers 982 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X70STC, a direct upgrade retaining the exact ISO 15552 mounting interface, TC trunnion mount, and output force.
The SAI replacement features an upgraded piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. It also adds SAIL, SAIF, and BSAI lock variants absent in the SI line. The original -S magnet supports CS1-B/DS1-B sensors, while SAI uses current AirTAC switches.
Airtac SI50 Standard Cylinder SI50X70STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X70STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X70STC |
| Bore size | Ø50 mm |
| Stroke | 70 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 SAI50X70STC 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 SAI50X70STC 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 SI50X70STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×70 | 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 SI50X70STC Is Used
Package Diversion
Ideal for pushing lightweight to medium cartons off a main conveyor line using the 982 N push force at 0.5 MPa without overwhelming the packaging.
Clamp Actuation
Provides reliable clamping pressure for machining fixtures, utilizing the 70 mm stroke to secure parts quickly before a cutting cycle begins.
Gate Control
Actuates sorting gates and material flow stops in distribution centers, benefiting from the TC trunnion mount for pivot motion.
Replacing the Airtac SI50 Standard Cylinder SI50X70STC with the SAI50X70STC
To replace the SI50X70STC, order the SAI50X70STC keeping the 50 mm bore, 70 mm stroke, TC trunnion mount, and -S magnet. Verify the G1/4 port and M16x1.5 rod thread. The SAI drops into existing ISO 15552 fixtures without changes. To size both ways: a neighbouring 63 mm bore offers 1559 N push at 0.5 MPa, while dropping to 40 mm yields 628 N. At 0.7 MPa this 50 mm unit pushes 1374 N. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X70STC
- ✓ 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 SI50X70STC FAQ
Yes, the SI50X70STC is discontinued. The direct replacement is the SAI50X70STC. It shares the same ISO 15552 mounting interface, 50 mm bore, 70 mm stroke, output force, and G1/4 port, fitting directly into existing fixtures.
This 50 mm bore cylinder uses a G1/4 air port. It delivers 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N at 0.9 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X70STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X70STC replacement — usually within 7-8 hours.