This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X25, 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 SI50X25
The AirTAC Airtac SI50 Standard Cylinder SI50X25 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 SAI50X25, 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 → SAI50X25
- 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 SI50X25
The AirTAC SI50X25 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 25mm stroke. It delivers a push force of 982 N and pull of 825 N at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI50X25, a direct replacement matching the exact ISO 15552 mounting interface, bore, stroke, force and port size.
The SAI upgrade features an improved piston seal with two Y-shaped one-way elements for low start-up pressure and long life. Note this specific SKU lacks a magnet (-S) and cannot accept a sensor. The SAI family also introduces SAIL, SAIF and BSAI lock variants absent in the SI line.
Airtac SI50 Standard Cylinder SI50X25 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X25 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X25 |
| 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 SAI50X25 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 SAI50X25 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 SI50X25
| 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 SI50X25 Is Used
Short-Stroke Clamping
Ideal for fixture clamping on machining lines where a compact 25mm stroke and 982 N force securely hold parts.
Package Diverting
Provides rapid actuation for diverting lightweight packages on conveyors, operating efficiently at 30-800 mm/s.
Gating Mechanisms
Drives short-throw gates in material handling systems, offering reliable 50 kg vertical lift capacity.
Replacing the Airtac SI50 Standard Cylinder SI50X25 with the SAI50X25
To replace the SI50X25, order the SAI50X25. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/4 port thread (PT, G or NPT) and the M16x1.5 rod end. Because this SKU has no magnet, it cannot hold a position sensor; if you need switching, select an SAI50X25S and use current AirTAC switches. Sizing both ways: a 50mm bore yields 982 N push at 0.5 MPa, while a neighbouring 63mm bore provides 1559 N. For load holding on air loss, note that a plain cylinder drifts and the cushion only decelerates; add an external pilot check valve or choose the SAIL lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X25
- ✓ 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 SI50X25 FAQ
Yes, the AirTAC SI50X25 is discontinued. The direct replacement is the SAI50X25. It shares the identical ISO 15552 mounting interface, 50mm bore, 25mm stroke, output force and G1/4 port, fitting directly into existing fixtures.
This double-acting cylinder uses a G1/4 air port. It generates a push force of 982 N and pull of 825 N at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Request a Quote for the SAI50X25
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X25 replacement — usually within 7-8 hours.